Phrenic Long-Term Facilitation Requires PKCθ Activity within Phrenic Motor Neurons

PubMed Central

Devinney, Michael J.; Fields, Daryl P.; Huxtable, Adrianne G.; Peterson, Timothy J.; Dale, Erica A.

2015-01-01

Acute intermittent hypoxia (AIH) induces a form of spinal motor plasticity known as phrenic long-term facilitation (pLTF); pLTF is a prolonged increase in phrenic motor output after AIH has ended. In anesthetized rats, we demonstrate that pLTF requires activity of the novel PKC isoform, PKCθ, and that the relevant PKCθ is within phrenic motor neurons. Whereas spinal PKCθ inhibitors block pLTF, inhibitors targeting other PKC isoforms do not. PKCθ is highly expressed in phrenic motor neurons, and PKCθ knockdown with intrapleural siRNAs abolishes pLTF. Intrapleural siRNAs targeting PKCζ, an atypical PKC isoform expressed in phrenic motor neurons that underlies a distinct form of phrenic motor plasticity, does not affect pLTF. Thus, PKCθ plays a critical role in spinal AIH-induced respiratory motor plasticity, and the relevant PKCθ is localized within phrenic motor neurons. Intrapleural siRNA delivery has considerable potential as a therapeutic tool to selectively manipulate plasticity in vital respiratory motor neurons. PMID:26019328

Enhanced multisensory integration and motor reactivation after active motor learning of audiovisual associations.

PubMed

Butler, Andrew J; James, Thomas W; James, Karin Harman

2011-11-01

Everyday experience affords us many opportunities to learn about objects through multiple senses using physical interaction. Previous work has shown that active motor learning of unisensory items enhances memory and leads to the involvement of motor systems during subsequent perception. However, the impact of active motor learning on subsequent perception and recognition of associations among multiple senses has not been investigated. Twenty participants were included in an fMRI study that explored the impact of active motor learning on subsequent processing of unisensory and multisensory stimuli. Participants were exposed to visuo-motor associations between novel objects and novel sounds either through self-generated actions on the objects or by observing an experimenter produce the actions. Immediately after exposure, accuracy, RT, and BOLD fMRI measures were collected with unisensory and multisensory stimuli in associative perception and recognition tasks. Response times during audiovisual associative and unisensory recognition were enhanced by active learning, as was accuracy during audiovisual associative recognition. The difference in motor cortex activation between old and new associations was greater for the active than the passive group. Furthermore, functional connectivity between visual and motor cortices was stronger after active learning than passive learning. Active learning also led to greater activation of the fusiform gyrus during subsequent unisensory visual perception. Finally, brain regions implicated in audiovisual integration (e.g., STS) showed greater multisensory gain after active learning than after passive learning. Overall, the results show that active motor learning modulates the processing of multisensory associations.

Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery.

PubMed

Keller, Martin; Taube, Wolfgang; Lauber, Benedikt

2018-02-22

Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions. The aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions. H-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest. In contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions. This study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Motor and non-motor circuitry activation induced by subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson’s disease patients: Intraoperative fMRI for DBS

PubMed Central

Knight, Emily J.; Testini, Paola; Min, Hoon-Ki; Gibson, William S.; Gorny, Krzysztof R.; Favazza, Christopher P.; Felmlee, Joel P.; Kim, Inyong; Welker, Kirk M.; Clayton, Daniel A.; Klassen, Bryan T.; Chang, Su-youne; Lee, Kendall H.

2015-01-01

Objective To test the hypothesis suggested by previous studies that subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with PD would affect the activity of both motor and non-motor networks, we applied intraoperative fMRI to patients receiving DBS. Patients and Methods Ten patients receiving STN DBS for PD underwent intraoperative 1.5T fMRI during high frequency stimulation delivered via an external pulse generator. The study was conducted between the dates of January 1, 2013 and September 30, 2014. Results We observed blood oxygen level dependent (BOLD) signal changes (FDR<.001) in the motor circuitry, including primary motor, premotor, and supplementary motor cortices, thalamus, pedunculopontine nucleus (PPN), and cerebellum, as well as in the limbic circuitry, including cingulate and insular cortices. Activation of the motor network was observed also after applying a Bonferroni correction (p<.001) to our dataset, suggesting that, across subjects, BOLD changes in the motor circuitry are more consistent compared to those occurring in the non-motor network. Conclusions These findings support the modulatory role of STN DBS on the activity of motor and non-motor networks, and suggest complex mechanisms at the basis of the efficacy of this treatment modality. Furthermore, these results suggest that, across subjects, BOLD changes in the motor circuitry are more consistent compared to those occurring in the non-motor network. With further studies combining the use of real time intraoperative fMRI with clinical outcomes in patients treated with DBS, functional imaging techniques have the potential not only to elucidate the mechanisms of DBS functioning, but also to guide and assist in the surgical treatment of patients affected by movement and neuropsychiatric disorders. PMID:26046412

Vibrissa motor cortex activity suppresses contralateral whisking behavior.

PubMed

Ebbesen, Christian Laut; Doron, Guy; Lenschow, Constanze; Brecht, Michael

2017-01-01

Anatomical, stimulation and lesion data implicate vibrissa motor cortex in whisker motor control. Work on motor cortex has focused on movement generation, but correlations between vibrissa motor cortex activity and whisking are weak. The exact role of vibrissa motor cortex remains unknown. We recorded vibrissa motor cortex neurons during various forms of vibrissal touch, which were invariably associated with whisker protraction and movement. Free whisking, object palpation and social touch all resulted in decreased cortical activity. To understand this activity decrease, we performed juxtacellular recordings, nanostimulation and in vivo whole-cell recordings. Social touch resulted in decreased spiking activity, decreased cell excitability and membrane hyperpolarization. Activation of vibrissa motor cortex by intracortical microstimulation elicited whisker retraction, as if to abort vibrissal touch. Various vibrissa motor cortex inactivation protocols resulted in contralateral protraction and increased whisker movements. These data collectively point to movement suppression as a prime function of vibrissa motor cortex activity.

Physical activity and motor decline in older persons.

PubMed

Buchman, A S; Boyle, P A; Wilson, R S; Bienias, Julia L; Bennett, D A

2007-03-01

We tested the hypothesis that physical activity modifies the course of age-related motor decline. More than 850 older participants of the Rush Memory and Aging Project underwent baseline assessment of physical activity and annual motor testing for up to 8 years. Nine strength measures and nine motor performance measures were summarized into composite measures of motor function. In generalized estimating equation models, global motor function declined during follow-up (estimate, -0.072; SE, 0.008; P < 0.001). Each additional hour of physical activity at baseline was associated with about a 5% decrease in the rate of global motor function decline (estimate, 0.004; SE, 0.001; P = 0.007). Secondary analyses suggested that the association of physical activity with motor decline was mostly due to the effect of physical activity on the rate of motor performance decline. Thus, higher levels of physical activity are associated with a slower rate of motor decline in older persons.

Can Motor Proficiency in Preschool Age Affect Physical Activity in Adolescence?

PubMed

Venetsanou, Fotini; Kambas, Antonis

2017-05-01

This study investigated if motor proficiency (MP) in preschool age associate with physical activity (PA) in adolescence. In 2004, the Bruininks-Oseretsky Test of Motor Proficiency-Short Form (BOTMP-SF) (7) was administered to 413 children, aged 4-6 years, who were classified to MP groups according to their BOTMP-SF total score (TS). In 2014, the PA of 106 former participants (47 boys, 59 girls) was measured with Omron pedometers. MP [three (high; above average; average)] × gender (two) ANOVA and Bonferroni tests were computed on average of steps/week. A significant interaction between the two factors was revealed (F = 15.27, p < .001, η 2 =.153), indicating that MP influenced male and female PA differently. Only in average MP group, males presented higher PA than females, whereas there were no differences between the two genders in the higher MP groups. Moreover, the only significant difference in PA among male groups was that between high and above average MP groups, while in females there were significant differences among all groups. High MP at preschool age positively associated with the PA in adolescence, especially in females. Emphasis on the development of proficient young movers might be beneficial for lifelong PA.

Manganese contamination affects the motor performance of wild northern quolls (Dasyurus hallucatus).

PubMed

Amir Abdul Nasir, Ami Fadhillah; Cameron, Skye F; Niehaus, Amanda C; Clemente, Christofer J; von Hippel, Frank A; Wilson, Robbie S

2018-05-21

Neuromotor deficits are an important sign of manganese (Mn) toxicity in humans and laboratory animals. However, the impacts of Mn exposure on the motor function of wild animals remains largely unknown. Here, we assessed the impact of chronic exposure to Mn from active mining operations on Groote Eylandt, Australia on the motor function of the semi-arboreal northern quoll (Dasyurus hallucatus), an endangered species. The three motor tests conducted-maximum sprint speed on a straight run, manoeuvrability around a corner, and motor control on a balance beam-showed that elevated Mn body burden did not diminish performance of these traits. However, quolls with higher Mn body burden approached a corner at a significantly narrower range of speeds, due to a significantly lower maximum approach speed. Slower speeds approaching a turn may reduce success at catching prey and avoiding predators. Given that maximum sprint speed on a straight run was not affected by Mn body burden, but maximum speed entering a corner was, slower speeds approaching a turn may reflect compensation for otherwise impaired performance in the turn. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hormone therapy in postmenopausal women affects hemispheric asymmetries in fine motor coordination.

PubMed

Bayer, Ulrike; Hausmann, Markus

2010-08-01

Evidence exists that the functional differences between the left and right cerebral hemispheres are affected by age. One prominent hypothesis proposes that frontal activity during cognitive task performance tends to be less lateralized in older than in younger adults, a pattern that has also been reported for motor functioning. Moreover, functional cerebral asymmetries (FCAs) have been shown to be affected by sex hormonal manipulations via hormone therapy (HT) in older women. Here, we investigate whether FCAs in fine motor coordination, as reflected by manual asymmetries (MAs), are susceptible to HT in older women. Therefore, sixty-two postmenopausal women who received hormone therapy either with estrogen (E) alone (n=15), an E-gestagen combination (n=21) or without HT (control group, n=26) were tested. Saliva levels of free estradiol and progesterone (P) were analyzed using chemiluminescence assays. MAs were measured with a finger tapping paradigm consisting of two different tapping conditions. As expected, postmenopausal controls without HT showed reduced MAs in simple (repetitive) finger tapping. In a more demanding sequential condition involving four fingers, however, they revealed enhanced MAs in favour of the dominant hand. This finding suggests an insufficient recruitment of critical motor brain areas (especially when the nondominant hand is used), probably as a result of age-related changes in corticocortical connectivity between motor areas. In contrast, both HT groups revealed reduced MAs in sequential finger tapping but an asymmetrical tapping performance related to estradiol levels in simple finger tapping. A similar pattern has previously been found in younger participants. The results suggest that, HT, and E exposure in particular, exerts positive effects on the motor system thereby counteracting an age-related reorganization. Copyright 2010 Elsevier Inc. All rights reserved.

Observing functional actions affects semantic processing of tools: evidence of a motor-to-semantic priming.

PubMed

De Bellis, Francesco; Ferrara, Antonia; Errico, Domenico; Panico, Francesco; Sagliano, Laura; Conson, Massimiliano; Trojano, Luigi

2016-01-01

Recent evidence shows that activation of motor information can favor identification of related tools, thus suggesting a strict link between motor and conceptual knowledge in cognitive representation of tools. However, the involvement of motor information in further semantic processing has not been elucidated. In three experiments, we aimed to ascertain whether motor information provided by observation of actions could affect processing of conceptual knowledge about tools. In Experiment 1, healthy participants judged whether pairs of tools evoking different functional handgrips had the same function. In Experiment 2 participants judged whether tools were paired with appropriate recipients. Finally, in Experiment 3 we again required functional judgments as in Experiment 1, but also included in the set of stimuli pairs of objects having different function and similar functional handgrips. In all experiments, pictures displaying either functional grasping (aimed to use tools) or structural grasping (just aimed to move tools independently from their use) were presented before each stimulus pair. The results demonstrated that, in comparison with structural grasping, observing functional grasping facilitates judgments about tools' function when objects did not imply the same functional manipulation (Experiment 1), whereas worsened such judgments when objects shared functional grasp (Experiment 3). Instead, action observation did not affect judgments concerning tool-recipient associations (Experiment 2). Our findings support a task-dependent influence of motor information on high-order conceptual tasks and provide further insights into how motor and conceptual processing about tools can interact.

BDNF Val66Met but not transcranial direct current stimulation affects motor learning after stroke.

PubMed

van der Vliet, Rick; Ribbers, Gerard M; Vandermeeren, Yves; Frens, Maarten A; Selles, Ruud W

tDCS is a non-invasive neuromodulation technique that has been reported to improve motor skill learning after stroke. However, the contribution of tDCS to motor skill learning has only been investigated in a small number of studies. In addition, it is unclear if tDCS effects are mediated by activity-dependent BDNF release and dependent on timing of tDCS relative to training. Investigate the role of activity-dependent BDNF release and timing of tDCS relative to training in motor skill learning. Double-blind, between-subjects randomized controlled trial of circuit tracing task improvement (ΔMotor skill) in 80 chronic stroke patients who underwent tDCS and were genotyped for BDNF Val66Met. Patients received either short-lasting tDCS (20 min) during training (short-lasting online group), long-lasting tDCS (10 min-25 min break - 10 min) one day before training (long-lasting offline group), short-lasting tDCS one day before training (short-lasting offline group), or sham tDCS. ΔMotor skill was defined as the skill difference on the circuit tracing task between day one and day nine of the study. Having at least one BDNF Met allele was found to diminish ΔMotor skill (β BDNF,Met  = -0.217 95%HDI = [-0.431 -0.0116]), indicating activity-dependent BDNF release is important for motor skill learning after stroke. However, none of the tDCS protocols affected ΔMotor skill (β Short-lasting,online  = 0.0908 95%HDI = [-0.227 0.403]; β Long-lasting,offline  = 0.0242 95%HDI = [-0.292 0.349]; β Short-lasting,offline  = -0.108 95%HDI = [-0.433 0.210]). BDNF Val66Met is a determinant of motor skill learning after stroke and could be important for prognostic models. tDCS does not modulate motor skill learning in our study and might be less effective than previously assumed. Copyright © 2017 Elsevier Inc. All rights reserved.

Self-modulation of primary motor cortex activity with motor and motor imagery tasks using real-time fMRI-based neurofeedback

PubMed Central

Berman, Brian D.; Horovitz, Silvina G.; Venkataraman, Gaurav; Hallett, Mark

2011-01-01

Advances in fMRI data acquisition and processing have made it possible to analyze brain activity as rapidly as the images are acquired allowing this information to be fed back to subjects in the scanner. The ability of subjects to learn to volitionally control localized brain activity within motor cortex using such real-time fMRI-based neurofeedback (NF) is actively being investigated as it may have clinical implications for motor rehabilitation after central nervous system injury and brain-computer interfaces. We investigated the ability of fifteen healthy volunteers to use NF to modulate brain activity within the primary motor cortex (M1) during a finger tapping and tapping imagery task. The M1 hand area ROI (ROIm) was functionally localized during finger tapping and a visual representation of BOLD signal changes within the ROIm fed back to the subject in the scanner. Surface EMG was used to assess motor output during tapping and ensure no motor activity was present during motor imagery task. Subjects quickly learned to modulate brain activity within their ROIm during the finger-tapping task, which could be dissociated from the magnitude of the tapping, but did not show a significant increase within the ROIm during the hand motor imagery task at the group level despite strongly activating a network consistent with the performance of motor imagery. The inability of subjects to modulate M1 proper with motor imagery may reflect an inherent difficulty in activating synapses in this area, with or without NF, since such activation may lead to M1 neuronal output and obligatory muscle activity. Future real-time fMRI-based NF investigations involving motor cortex may benefit from focusing attention on cortical regions other than M1 for feedback training or alternative feedback strategies such as measures of functional connectivity within the motor system. PMID:21803163

Dynamic Modulation of Human Motor Activity When Observing Actions

PubMed Central

Press, Clare; Cook, Jennifer; Blakemore, Sarah-Jayne; Kilner, James

2012-01-01

Previous studies have demonstrated that when we observe somebody else executing an action many areas of our own motor systems are active. It has been argued that these motor activations are evidence that we motorically simulate observed actions; this motoric simulation may support various functions such as imitation and action understanding. However, whether motoric simulation is indeed the function of motor activations during action observation is controversial, due to inconsistency in findings. Previous studies have demonstrated dynamic modulations in motor activity when we execute actions. Therefore, if we do motorically simulate observed actions, our motor systems should also be modulated dynamically, and in a corresponding fashion, during action observation. Using magnetoencephalography, we recorded the cortical activity of human participants while they observed actions performed by another person. Here, we show that activity in the human motor system is indeed modulated dynamically during action observation. The finding that activity in the motor system is modulated dynamically when observing actions can explain why studies of action observation using functional magnetic resonance imaging have reported conflicting results, and is consistent with the hypothesis that we motorically simulate observed actions. PMID:21414901

Dopamine Promotes Motor Cortex Plasticity and Motor Skill Learning via PLC Activation

PubMed Central

Rioult-Pedotti, Mengia-Seraina; Pekanovic, Ana; Atiemo, Clement Osei; Marshall, John; Luft, Andreas Rüdiger

2015-01-01

Dopaminergic neurons in the ventral tegmental area, the major midbrain nucleus projecting to the motor cortex, play a key role in motor skill learning and motor cortex synaptic plasticity. Dopamine D1 and D2 receptor antagonists exert parallel effects in the motor system: they impair motor skill learning and reduce long-term potentiation. Traditionally, D1 and D2 receptor modulate adenylyl cyclase activity and cyclic adenosine monophosphate accumulation in opposite directions via different G-proteins and bidirectionally modulate protein kinase A (PKA), leading to distinct physiological and behavioral effects. Here we show that D1 and D2 receptor activity influences motor skill acquisition and long term synaptic potentiation via phospholipase C (PLC) activation in rat primary motor cortex. Learning a new forelimb reaching task is severely impaired in the presence of PLC, but not PKA-inhibitor. Similarly, long term potentiation in motor cortex, a mechanism involved in motor skill learning, is reduced when PLC is inhibited but remains unaffected by the PKA inhibitor. Skill learning deficits and reduced synaptic plasticity caused by dopamine antagonists are prevented by co-administration of a PLC agonist. These results provide evidence for a role of intracellular PLC signaling in motor skill learning and associated cortical synaptic plasticity, challenging the traditional view of bidirectional modulation of PKA by D1 and D2 receptors. These findings reveal a novel and important action of dopamine in motor cortex that might be a future target for selective therapeutic interventions to support learning and recovery of movement resulting from injury and disease. PMID:25938462

Enhanced Multisensory Integration and Motor Reactivation after Active Motor Learning of Audiovisual Associations

ERIC Educational Resources Information Center

Butler, Andrew J.; James, Thomas W.; James, Karin Harman

2011-01-01

Everyday experience affords us many opportunities to learn about objects through multiple senses using physical interaction. Previous work has shown that active motor learning of unisensory items enhances memory and leads to the involvement of motor systems during subsequent perception. However, the impact of active motor learning on subsequent…

Unilateral nasal obstruction affects motor representation development within the face primary motor cortex in growing rats.

PubMed

Abe, Yasunori; Kato, Chiho; Uchima Koecklin, Karin Harumi; Okihara, Hidemasa; Ishida, Takayoshi; Fujita, Koichi; Yabushita, Tadachika; Kokai, Satoshi; Ono, Takashi

2017-06-01

Postnatal growth is influenced by genetic and environmental factors. Nasal obstruction during growth alters the electromyographic activity of orofacial muscles. The facial primary motor area represents muscles of the tongue and jaw, which are essential in regulating orofacial motor functions, including chewing and jaw opening. This study aimed to evaluate the effect of chronic unilateral nasal obstruction during growth on the motor representations within the face primary motor cortex (M1). Seventy-two 6-day-old male Wistar rats were randomly divided into control ( n = 36) and experimental ( n = 36) groups. Rats in the experimental group underwent unilateral nasal obstruction after cauterization of the external nostril at 8 days of age. Intracortical microstimulation (ICMS) mapping was performed when the rats were 5, 7, 9, and 11 wk old in control and experimental groups ( n = 9 per group per time point). Repeated-measures multivariate ANOVA was used for intergroup and intragroup statistical comparisons. In the control and experimental groups, the total number of positive ICMS sites for the genioglossus and anterior digastric muscles was significantly higher at 5, 7, and 9 wk, but there was no significant difference between 9 and 11 wk of age. Moreover, the total number of positive ICMS sites was significantly smaller in the experimental group than in the control at each age. It is possible that nasal obstruction induced the initial changes in orofacial motor behavior in response to the altered respiratory pattern, which eventually contributed to face-M1 neuroplasticity. NEW & NOTEWORTHY Unilateral nasal obstruction in rats during growth periods induced changes in arterial oxygen saturation (SpO 2 ) and altered development of the motor representation within the face primary cortex. Unilateral nasal obstruction occurring during growth periods may greatly affect not only respiratory function but also craniofacial function in rats. Nasal obstruction should be treated

Side of symptom onset affects motor dysfunction in Parkinson's disease.

PubMed

Haaxma, C A; Helmich, R C G; Borm, G F; Kappelle, A C; Horstink, M W I M; Bloem, B R

2010-11-10

The healthy brain appears to have an asymmetric dopamine distribution, with higher levels of dopamine in the left than in the right striatum. Here, we test the hypothesis that this neurochemical asymmetry renders the right striatum relatively more vulnerable to the effects of dopaminergic denervation in Parkinson's disease (PD). Using the pegboard dexterity test, we compared motor performance of both hands between healthy subjects (n=48), PD patients with predominantly right-hemispheric dopamine depletion (PD-RIGHT; n=83) and PD patients with more severe left-hemispheric dopamine depletion (PD-LEFT; n=103). All subjects were right-handed. After adjusting for hand-dominance effects, we found that PD-RIGHT patients exhibited a 55% larger difference between right and left dexterity scores than PD-LEFT patients. This effect could be attributed to greater motor dysfunction of the more-affected hand in PD-RIGHT patients, while the less-affected hand performed similarly in both groups. We conclude that the side of symptom onset affects motor dysfunction in PD, and suggest that the non-dominant right hemisphere may be more susceptible to dopaminergic denervation than the dominant left hemisphere. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Laboratory Activities for Life Span Motor Development.

ERIC Educational Resources Information Center

Haywood, Kathleen M.

This manual describes motor development laboratory activities to help future physical education teachers observe, assess, measure, and test students' motor skills. A total of 20 laboratory activities are described under five sections geared toward: (1) physical growth and maturation; (2) assessing early motor development; (3) assessing basic motor…

Aberrant supplementary motor complex and limbic activity during motor preparation in motor conversion disorder

PubMed Central

Voon, V; Brezing, C; Gallea, C; Hallett, M

2014-01-01

Background Conversion disorder is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that conversion disorder with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amgydala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Methods Subjects performed either an internally or externally generated two-button action selection task in a functional MRI study. Results Eleven conversion disorder patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. Conclusion We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system which is both hypoactive and functionally disconnected from prefrontal top-down regulation. PMID:21935985

Aberrant supplementary motor complex and limbic activity during motor preparation in motor conversion disorder.

PubMed

Voon, Valerie; Brezing, Christina; Gallea, Cecile; Hallett, Mark

2011-11-01

Conversion disorder (CD) is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that CD with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amygdala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Subjects performed either an internally or externally generated 2-button action selection task in a functional MRI study. Eleven CD patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula, and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system, which is both hypoactive and functionally disconnected from prefrontal top-down regulation. Copyright © 2011 Movement Disorder Society.

The association between brain activity and motor imagery during motor illusion induction by vibratory stimulation.

PubMed

Kodama, Takayuki; Nakano, Hideki; Katayama, Osamu; Murata, Shin

2017-01-01

The association between motor imagery ability and brain neural activity that leads to the manifestation of a motor illusion remains unclear. In this study, we examined the association between the ability to generate motor imagery and brain neural activity leading to the induction of a motor illusion by vibratory stimulation. The sample consisted of 20 healthy individuals who did not have movement or sensory disorders. We measured the time between the starting and ending points of a motor illusion (the time to illusion induction, TII) and performed electroencephalography (EEG). We conducted a temporo-spatial analysis on brain activity leading to the induction of motor illusions using the EEG microstate segmentation method. Additionally, we assessed the ability to generate motor imagery using the Japanese version of the Movement Imagery Questionnaire-Revised (JMIQ-R) prior to performing the task and examined the associations among brain neural activity levels as identified by microstate segmentation method, TII, and the JMIQ-R scores. The results showed four typical microstates during TII and significantly higher neural activity in the ventrolateral prefrontal cortex, primary sensorimotor area, supplementary motor area (SMA), and inferior parietal lobule (IPL). Moreover, there were significant negative correlations between the neural activity of the primary motor cortex (MI), SMA, IPL, and TII, and a significant positive correlation between the neural activity of the SMA and the JMIQ-R scores. These findings suggest the possibility that a neural network primarily comprised of the neural activity of SMA and M1, which are involved in generating motor imagery, may be the neural basis for inducing motor illusions. This may aid in creating a new approach to neurorehabilitation that enables a more robust reorganization of the neural base for patients with brain dysfunction with a motor function disorder.

The association between brain activity and motor imagery during motor illusion induction by vibratory stimulation

PubMed Central

Kodama, Takayuki; Nakano, Hideki; Katayama, Osamu; Murata, Shin

2017-01-01

Background: The association between motor imagery ability and brain neural activity that leads to the manifestation of a motor illusion remains unclear. Objective: In this study, we examined the association between the ability to generate motor imagery and brain neural activity leading to the induction of a motor illusion by vibratory stimulation. Methods: The sample consisted of 20 healthy individuals who did not have movement or sensory disorders. We measured the time between the starting and ending points of a motor illusion (the time to illusion induction, TII) and performed electroencephalography (EEG). We conducted a temporo-spatial analysis on brain activity leading to the induction of motor illusions using the EEG microstate segmentation method. Additionally, we assessed the ability to generate motor imagery using the Japanese version of the Movement Imagery Questionnaire-Revised (JMIQ-R) prior to performing the task and examined the associations among brain neural activity levels as identified by microstate segmentation method, TII, and the JMIQ-R scores. Results: The results showed four typical microstates during TII and significantly higher neural activity in the ventrolateral prefrontal cortex, primary sensorimotor area, supplementary motor area (SMA), and inferior parietal lobule (IPL). Moreover, there were significant negative correlations between the neural activity of the primary motor cortex (MI), SMA, IPL, and TII, and a significant positive correlation between the neural activity of the SMA and the JMIQ-R scores. Conclusion: These findings suggest the possibility that a neural network primarily comprised of the neural activity of SMA and M1, which are involved in generating motor imagery, may be the neural basis for inducing motor illusions. This may aid in creating a new approach to neurorehabilitation that enables a more robust reorganization of the neural base for patients with brain dysfunction with a motor function disorder. PMID:29172013

Escape from harm: linking affective vision and motor responses during active avoidance

PubMed Central

Keil, Andreas

2014-01-01

When organisms confront unpleasant objects in their natural environments, they engage in behaviors that allow them to avoid aversive outcomes. Here, we linked visual processing of threat to its behavioral consequences by including a motor response that terminated exposure to an aversive event. Dense-array steady-state visual evoked potentials were recorded in response to conditioned threat and safety signals viewed in active or passive behavioral contexts. The amplitude of neuronal responses in visual cortex increased additively, as a function of emotional value and action relevance. The gain in local cortical population activity for threat relative to safety cues persisted when aversive reinforcement was behaviorally terminated, suggesting a lingering emotionally based response amplification within the visual system. Distinct patterns of long-range neural synchrony emerged between the visual cortex and extravisual regions. Increased coupling between visual and higher-order structures was observed specifically during active perception of threat, consistent with a reorganization of neuronal populations involved in linking sensory processing to action preparation. PMID:24493849

Large motor units are selectively affected following a stroke.

PubMed

Lukács, M; Vécsei, L; Beniczky, S

2008-11-01

Previous studies have revealed a loss of functioning motor units in stroke patients. However, it remained unclear whether the motor units are affected randomly or in some specific pattern. We assessed whether there is a selective loss of the large (high recruitment threshold) or the small (low recruitment threshold) motor units following a stroke. Forty-five stroke patients and 40 healthy controls participated in the study. Macro-EMG was recorded from the abductor digiti minimi muscle at two levels of force output (low and high). The median macro motor unit potential (macro-MUP) amplitude on the paretic side was compared with those on the unaffected side and in the controls. In the control group and on the unaffected side, the macro-MUPs were significantly larger at the high force output than at the low one. However, on the paretic side the macro-MUPs at the high force output had the same amplitude as those recorded at the low force output. These changes correlated with the severity of the paresis. Following a stroke, there is a selective functional loss of the large, high-threshold motor units. These changes are related to the severity of the symptoms. Our findings furnish further insight into the pathophysiology of the motor deficit following a stroke.

High variability impairs motor learning regardless of whether it affects task performance.

PubMed

Cardis, Marco; Casadio, Maura; Ranganathan, Rajiv

2018-01-01

Motor variability plays an important role in motor learning, although the exact mechanisms of how variability affects learning are not well understood. Recent evidence suggests that motor variability may have different effects on learning in redundant tasks, depending on whether it is present in the task space (where it affects task performance) or in the null space (where it has no effect on task performance). We examined the effect of directly introducing null and task space variability using a manipulandum during the learning of a motor task. Participants learned a bimanual shuffleboard task for 2 days, where their goal was to slide a virtual puck as close as possible toward a target. Critically, the distance traveled by the puck was determined by the sum of the left- and right-hand velocities, which meant that there was redundancy in the task. Participants were divided into five groups, based on both the dimension in which the variability was introduced and the amount of variability that was introduced during training. Results showed that although all groups were able to reduce error with practice, learning was affected more by the amount of variability introduced rather than the dimension in which variability was introduced. Specifically, groups with higher movement variability during practice showed larger errors at the end of practice compared with groups that had low variability during learning. These results suggest that although introducing variability can increase exploration of new solutions, this may adversely affect the ability to retain the learned solution. NEW & NOTEWORTHY We examined the role of introducing variability during motor learning in a redundant task. The presence of redundancy allows variability to be introduced in different dimensions: the task space (where it affects task performance) or the null space (where it does not affect task performance). We found that introducing variability affected learning adversely, but the amount of

Altered cortico-basal ganglia motor pathways reflect reduced volitional motor activity in schizophrenia.

PubMed

Bracht, Tobias; Schnell, Susanne; Federspiel, Andrea; Razavi, Nadja; Horn, Helge; Strik, Werner; Wiest, Roland; Dierks, Thomas; Müller, Thomas J; Walther, Sebastian

2013-02-01

Little is known about the neurobiology of hypokinesia in schizophrenia. Therefore, the aim of this study was to investigate alterations of white matter motor pathways in schizophrenia and to relate our findings to objectively measured motor activity. We examined 21 schizophrenia patients and 21 healthy controls using diffusion tensor imaging and actigraphy. We applied a probabilistic fibre tracking approach to investigate pathways connecting the dorsolateral prefrontal cortex (dlPFC), the rostral anterior cingulate cortex (rACC), the pre-supplementary motor area (pre-SMA), the supplementary motor area proper (SMA-proper), the primary motor cortex (M1), the caudate nucleus, the striatum, the pallidum and the thalamus. Schizophrenia patients had lower activity levels than controls. In schizophrenia we found higher probability indices forming part of a bundle of interest (PIBI) in pathways connecting rACC, pre-SMA and SMA-proper as well as in pathways connecting M1 and pre-SMA with caudate nucleus, putamen, pallidum and thalamus and a reduced spatial extension of motor pathways in schizophrenia. There was a positive correlation between PIBI and activity level in the right pre-SMA-pallidum and the left M1-thalamus connection in healthy controls, and in the left pre-SMA-SMA-proper pathway in schizophrenia. Our results point to reduced volitional motor activity and altered motor pathway organisation in schizophrenia. The identified associations between the amount of movement and structural connectivity of motor pathways suggest dysfunction of cortico-basal ganglia pathways in the pathophysiology of hypokinesia in schizophrenia. Schizophrenia patients may use cortical pathways involving the supplementary motor area to compensate for basal ganglia dysfunction. Copyright © 2012 Elsevier B.V. All rights reserved.

Neurofeedback-based functional near-infrared spectroscopy upregulates motor cortex activity in imagined motor tasks

PubMed Central

Lapborisuth, Pawan; Zhang, Xian; Noah, Adam; Hirsch, Joy

2017-01-01

Abstract. Neurofeedback is a method for using neural activity displayed on a computer to regulate one’s own brain function and has been shown to be a promising technique for training individuals to interact with brain–machine interface applications such as neuroprosthetic limbs. The goal of this study was to develop a user-friendly functional near-infrared spectroscopy (fNIRS)-based neurofeedback system to upregulate neural activity associated with motor imagery, which is frequently used in neuroprosthetic applications. We hypothesized that fNIRS neurofeedback would enhance activity in motor cortex during a motor imagery task. Twenty-two participants performed active and imaginary right-handed squeezing movements using an elastic ball while wearing a 98-channel fNIRS device. Neurofeedback traces representing localized cortical hemodynamic responses were graphically presented to participants in real time. Participants were instructed to observe this graphical representation and use the information to increase signal amplitude. Neural activity was compared during active and imaginary squeezing with and without neurofeedback. Active squeezing resulted in activity localized to the left premotor and supplementary motor cortex, and activity in the motor cortex was found to be modulated by neurofeedback. Activity in the motor cortex was also shown in the imaginary squeezing condition only in the presence of neurofeedback. These findings demonstrate that real-time fNIRS neurofeedback is a viable platform for brain–machine interface applications. PMID:28680906

Neurofeedback-based functional near-infrared spectroscopy upregulates motor cortex activity in imagined motor tasks.

PubMed

Lapborisuth, Pawan; Zhang, Xian; Noah, Adam; Hirsch, Joy

2017-04-01

Neurofeedback is a method for using neural activity displayed on a computer to regulate one's own brain function and has been shown to be a promising technique for training individuals to interact with brain-machine interface applications such as neuroprosthetic limbs. The goal of this study was to develop a user-friendly functional near-infrared spectroscopy (fNIRS)-based neurofeedback system to upregulate neural activity associated with motor imagery, which is frequently used in neuroprosthetic applications. We hypothesized that fNIRS neurofeedback would enhance activity in motor cortex during a motor imagery task. Twenty-two participants performed active and imaginary right-handed squeezing movements using an elastic ball while wearing a 98-channel fNIRS device. Neurofeedback traces representing localized cortical hemodynamic responses were graphically presented to participants in real time. Participants were instructed to observe this graphical representation and use the information to increase signal amplitude. Neural activity was compared during active and imaginary squeezing with and without neurofeedback. Active squeezing resulted in activity localized to the left premotor and supplementary motor cortex, and activity in the motor cortex was found to be modulated by neurofeedback. Activity in the motor cortex was also shown in the imaginary squeezing condition only in the presence of neurofeedback. These findings demonstrate that real-time fNIRS neurofeedback is a viable platform for brain-machine interface applications.

Lost for emotion words: What motor and limbic brain activity reveals about autism and semantic theory

PubMed Central

Moseley, Rachel L.; Shtyrov, Yury; Mohr, Bettina; Lombardo, Michael V.; Baron-Cohen, Simon; Pulvermüller, Friedemann

2015-01-01

Autism spectrum conditions (ASC) are characterised by deficits in understanding and expressing emotions and are frequently accompanied by alexithymia, a difficulty in understanding and expressing emotion words. Words are differentially represented in the brain according to their semantic category and these difficulties in ASC predict reduced activation to emotion-related words in limbic structures crucial for affective processing. Semantic theories view ‘emotion actions’ as critical for learning the semantic relationship between a word and the emotion it describes, such that emotion words typically activate the cortical motor systems involved in expressing emotion actions such as facial expressions. As ASC are also characterised by motor deficits and atypical brain structure and function in these regions, motor structures would also be expected to show reduced activation during emotion-semantic processing. Here we used event-related fMRI to compare passive processing of emotion words in comparison to abstract verbs and animal names in typically-developing controls and individuals with ASC. Relatively reduced brain activation in ASC for emotion words, but not matched control words, was found in motor areas and cingulate cortex specifically. The degree of activation evoked by emotion words in the motor system was also associated with the extent of autistic traits as revealed by the Autism Spectrum Quotient. We suggest that hypoactivation of motor and limbic regions for emotion word processing may underlie difficulties in processing emotional language in ASC. The role that sensorimotor systems and their connections might play in the affective and social-communication difficulties in ASC is discussed. PMID:25278250

Motor activation in patients with Pantothenate-Kinase Associated Neurodegeneration: a functional magnetic resonance imaging study.

PubMed

Stoeter, P; Rodriguez-Raecke, R; Vilchez, C; Perez-Then, E; Speckter, H; Oviedo, J; Roa-Sanchez, P

2012-11-01

In a variety of dystonias, functional magnetic resonance imaging has shown deviations of cortical and basal ganglia activations within the motor network, which might cause the movement disturbances. Because these investigations have never been performed in secondary dystonia due to Pantothenate-Kinase Associated Neurodegeneration, we report our results in a small group of such patients from the Dominican Republic. Functional magnetic resonance imaging was carried out in 7 patients with a genetically confirmed mutation of the PANK2 gene and a non-affected control group (matched pairs) using an event-related motor activation paradigm (hand movements). Compared to the control group (p ≤ 0.01), patients showed a larger amount of activated voxels starting in the contralateral cerebellum and contralateral premotor cortex 2 s before the actual hand movement. Whereas these "hyperactivations" gradually diminished over time, activations in the contralateral primary motor cortex and the supplementary motor area peaked during the next second and those of the contralateral putamen at the time of the actual hand movement. In a multiple regression analysis, all these areas correlated positively with the degree of dystonia of the contralateral arm as judged by the Burke-Fahn-Marsden-scale (p ≤ 0.001). As in other forms of dystonia, the increased activations of the motor system found in our patients could be related to the origin of the dystonic movements. Because in this condition the primary lesion affects the pallidum, a defect of the feed-back control mechanism between basal ganglia and cortex might be the responsible factor. © 2012 Elsevier Ltd. All rights reserved.

Disrupting vagal feedback affects birdsong motor control.

PubMed

Méndez, Jorge M; Dall'asén, Analía G; Goller, Franz

2010-12-15

Coordination of different motor systems for sound production involves the use of feedback mechanisms. Song production in oscines is a well-established animal model for studying learned vocal behavior. Whereas the online use of auditory feedback has been studied in the songbird model, very little is known about the role of other feedback mechanisms. Auditory feedback is required for the maintenance of stereotyped adult song. In addition, the use of somatosensory feedback to maintain pressure during song has been demonstrated with experimentally induced fluctuations in air sac pressure. Feedback information mediating this response is thought to be routed to the central nervous system via afferent fibers of the vagus nerve. Here, we tested the effects of unilateral vagotomy on the peripheral motor patterns of song production and the acoustic features. Unilateral vagotomy caused a variety of disruptions and alterations to the respiratory pattern of song, some of which affected the acoustic structure of vocalizations. These changes were most pronounced a few days after nerve resection and varied between individuals. In the most extreme cases, the motor gestures of respiration were so severely disrupted that individual song syllables or the song motif were atypically terminated. Acoustic changes also suggest altered use of the two sound generators and upper vocal tract filtering, indicating that the disruption of vagal feedback caused changes to the motor program of all motor systems involved in song production and modification. This evidence for the use of vagal feedback by the song system with disruption of song during the first days after nerve cut provides a contrast to the longer-term effects of auditory feedback disruption. It suggests a significant role for somatosensory feedback that differs from that of auditory feedback.

Disrupting vagal feedback affects birdsong motor control

PubMed Central

Méndez, Jorge M.; Dall'Asén, Analía G.; Goller, Franz

2010-01-01

Coordination of different motor systems for sound production involves the use of feedback mechanisms. Song production in oscines is a well-established animal model for studying learned vocal behavior. Whereas the online use of auditory feedback has been studied in the songbird model, very little is known about the role of other feedback mechanisms. Auditory feedback is required for the maintenance of stereotyped adult song. In addition, the use of somatosensory feedback to maintain pressure during song has been demonstrated with experimentally induced fluctuations in air sac pressure. Feedback information mediating this response is thought to be routed to the central nervous system via afferent fibers of the vagus nerve. Here, we tested the effects of unilateral vagotomy on the peripheral motor patterns of song production and the acoustic features. Unilateral vagotomy caused a variety of disruptions and alterations to the respiratory pattern of song, some of which affected the acoustic structure of vocalizations. These changes were most pronounced a few days after nerve resection and varied between individuals. In the most extreme cases, the motor gestures of respiration were so severely disrupted that individual song syllables or the song motif were atypically terminated. Acoustic changes also suggest altered use of the two sound generators and upper vocal tract filtering, indicating that the disruption of vagal feedback caused changes to the motor program of all motor systems involved in song production and modification. This evidence for the use of vagal feedback by the song system with disruption of song during the first days after nerve cut provides a contrast to the longer-term effects of auditory feedback disruption. It suggests a significant role for somatosensory feedback that differs from that of auditory feedback. PMID:21113000

Motor experience with a sport-specific implement affects motor imagery

PubMed Central

Zhu, Hua; Shen, Cheng; Zhang, Jian

2018-01-01

The present study tested whether sport-specific implements facilitate motor imagery, whereas nonspecific implements disrupt motor imagery. We asked a group of basketball players (experts) and a group of healthy controls (novices) to physically perform (motor execution) and mentally simulate (motor imagery) basketball throws. Subjects produced motor imagery when they were holding a basketball, a volleyball, or nothing. Motor imagery performance was measured by temporal congruence, which is the correspondence between imagery and execution times estimated as (imagery time minus execution time) divided by (imagery time plus execution time), as well as the vividness of motor imagery. Results showed that experts produced greater temporal congruence and vividness of kinesthetic imagery while holding a basketball compared to when they were holding nothing, suggesting a facilitation effect from sport-specific implements. In contrast, experts produced lower temporal congruence and vividness of kinesthetic imagery while holding a volleyball compared to when they were holding nothing, suggesting the interference effect of nonspecific implements. Furthermore, we found a negative correlation between temporal congruence and the vividness of kinesthetic imagery in experts while holding a basketball. On the contrary, the implement manipulation did not modulate the temporal congruence of novices. Our findings suggest that motor representation in experts is built on motor experience associated with specific-implement use and thus was subjected to modulation of the implement held. We conclude that sport-specific implements facilitate motor imagery, whereas nonspecific implements could disrupt motor representation in experts. PMID:29719738

Aversive stimuli exacerbate defensive motor behaviour in motor conversion disorder.

PubMed

Blakemore, Rebekah L; Sinanaj, Indrit; Galli, Silvio; Aybek, Selma; Vuilleumier, Patrik

2016-12-01

Conversion disorder or functional neurological symptom disorder (FND) can affect the voluntary motor system, without an organic cause. Functional symptoms are thought to be generated unconsciously, arising from underlying psychological stressors. However, attempts to demonstrate a direct relationship between the limbic system and disrupted motor function in FND are lacking. We tested whether negative affect would exacerbate alterations of motor control and corresponding brain activations in individuals with FND. Ten patients and ten healthy controls produced an isometric precision-grip contraction at 10% of maximum force while either viewing visual feedback of their force output, or unpleasant or pleasant emotional images (without feedback). Force magnitude was continuously recorded together with change in brain activity using fMRI. For controls, force output decayed from the target level while viewing pleasant and unpleasant images. Patients however, maintained force at the target level without decay while viewing unpleasant images, indicating a pronounced effect of negative affect on force output in FND. This emotional modulation of force control was associated with different brain activation patterns between groups. Contrasting the unpleasant with the pleasant condition, controls showed increased activity in the inferior frontal cortex and pre-supplementary motor area, whereas patients had greater activity in the cerebellum (vermis), posterior cingulate cortex, and hippocampus. Engagement of a cerebellar-limbic network in patients is consistent with heightened processing of emotional salience, and supports the role of the cerebellum in freezing responses in the presence of aversive events. These data highlight a possible neural circuit through which psychological stressors elicit defensive behaviour and modulate motor function in FND. Copyright © 2016 Elsevier Ltd. All rights reserved.

Activity Regulates the Incidence of Heteronymous Sensory-Motor Connections

PubMed Central

Mendelsohn, Alana I.; Simon, Christian M.; Abbott, L. F.; Mentis, George Z.; Jessell, Thomas M.

2015-01-01

Summary The construction of spinal sensory-motor circuits involves the selection of appropriate synaptic partners and the allocation of precise synaptic input densities. Many aspects of spinal sensory-motor selectivity appear to be preserved when peripheral sensory activation is blocked, which has led to a view that sensory-motor circuits are assembled in an activity-independent manner. Yet it remains unclear whether activity-dependent refinement has a role in the establishment of connections between sensory afferents and those motor pools that have synergistic biomechanical functions. We show here that genetically abolishing central sensory-motor neurotransmission leads to a selective enhancement in the number and density of such “heteronymous” connections, whereas other aspects of sensory-motor connectivity are preserved. Spike-timing dependent synaptic refinement represents one possible mechanism for the changes in connectivity observed after activity blockade. Our findings therefore reveal that sensory activity does have a limited and selective role in the establishment of patterned monosynaptic sensory-motor connections. PMID:26094608

The Effects of the Interplay between Motor and Brownian Forces on the Rheology of Active Gels.

PubMed

Córdoba, Andrés

2018-04-19

Active gels perform key mechanical roles inside the cell, such as cell division, motion, and force sensing. The unique mechanical properties required to perform such functions arise from the interactions between molecular motors and semiflexible polymeric filaments. Molecular motors can convert the energy released in the hydrolysis of ATP into forces of up to piconewton magnitudes. Moreover, the polymeric filaments that form active gels are flexible enough to respond to Brownian forces but also stiff enough to support the large tensions induced by the motor-generated forces. Brownian forces are expected to have a significant effect especially at motor activities at which stable noncontractile in vitro active gels are prepared for rheological measurements. Here, a microscopic mean-field theory of active gels originally formulated in the limit of motor-dominated dynamics is extended to include Brownian forces. In the model presented here, Brownian forces are included accurately, at real room temperature, even in systems with high motor activity. It is shown that a subtle interplay, or competition, between motor-generated forces and Brownian forces has an important impact on the mass transport and rheological properties of active gels. The model predictions show that at low frequencies the dynamic modulus of active gels is determined mostly by motor protein dynamics. However, Brownian forces significantly increase the breadth of the relaxation spectrum and can affect the shape of the dynamic modulus over a wide frequency range even for ratios of motor to Brownian forces of more than a hundred. Since the ratio between motor and Brownian forces is sensitive to ATP concentration, the results presented here shed some light on how the transient mechanical response of active gels changes with varying ATP concentration.

Network properties of interstitial cells of Cajal affect intestinal pacemaker activity and motor patterns, according to a mathematical model of weakly coupled oscillators.

PubMed

Wei, Ruihan; Parsons, Sean P; Huizinga, Jan D

2017-03-01

What is the central question of this study? What are the effects of interstitial cells of Cajal (ICC) network perturbations on intestinal pacemaker activity and motor patterns? What is the main finding and its importance? Two-dimensional modelling of the ICC pacemaker activity according to a phase model of weakly coupled oscillators showed that network properties (coupling strength between oscillators, frequency gradient and frequency noise) strongly influence pacemaker network activity and subsequent motor patterns. The model explains motor patterns observed in physiological conditions and provides predictions and testable hypotheses for effects of ICC loss and frequency modulation on the motor patterns. Interstitial cells of Cajal (ICC) are the pacemaker cells of gut motility and are associated with motility disorders. Interstitial cells of Cajal form a network, but the contributions of its network properties to gut physiology and dysfunction are poorly understood. We modelled an ICC network as a two-dimensional network of weakly coupled oscillators with a frequency gradient and showed changes over time in video and graphical formats. Model parameters were obtained from slow-wave-driven contraction patterns in the mouse intestine and pacemaker slow-wave activities from the cat intestine. Marked changes in propagating oscillation patterns (including changes from propagation to non-propagating) were observed by changing network parameters (coupling strength between oscillators, the frequency gradient and frequency noise), which affected synchronization, propagation velocity and occurrence of dislocations (termination of an oscillation). Complete uncoupling of a circumferential ring of oscillators caused the proximal and distal section to desynchronize, but complete synchronization was maintained with only a single oscillator connecting the sections with high enough coupling. The network of oscillators could withstand loss; even with 40% of oscillators lost randomly

Reduced Motor Cortex Activity during Movement Preparation following a Period of Motor Skill Practice

PubMed Central

Wright, David J.; Holmes, Paul; Di Russo, Francesco; Loporto, Michela; Smith, Dave

2012-01-01

Experts in a skill produce movement-related cortical potentials (MRCPs) of smaller amplitude and later onset than novices. This may indicate that, following long-term training, experts require less effort to plan motor skill performance. However, no longitudinal evidence exists to support this claim. To address this, EEG was used to study the effect of motor skill training on cortical activity related to motor planning. Ten non-musicians took part in a 5-week training study learning to play guitar. At week 1, the MRCP was recorded from motor areas whilst participants played the G Major scale. Following a period of practice of the scale, the MRCP was recorded again at week 5. Results showed that the amplitude of the later pre-movement components were smaller at week 5 compared to week 1. This may indicate that, following training, less activity at motor cortex sites is involved in motor skill preparation. This supports claims for a more efficient motor preparation following motor skill training. PMID:23251647

A Map of Anticipatory Activity in Mouse Motor Cortex.

PubMed

Chen, Tsai-Wen; Li, Nuo; Daie, Kayvon; Svoboda, Karel

2017-05-17

Activity in the mouse anterior lateral motor cortex (ALM) instructs directional movements, often seconds before movement initiation. It is unknown whether this preparatory activity is localized to ALM or widely distributed within motor cortex. Here we imaged activity across motor cortex while mice performed a whisker-based object localization task with a delayed, directional licking response. During tactile sensation and the delay epoch, object location was represented in motor cortex areas that are medial and posterior relative to ALM, including vibrissal motor cortex. Preparatory activity appeared first in deep layers of ALM, seconds before the behavioral response, and remained localized to ALM until the behavioral response. Later, widely distributed neurons represented the outcome of the trial. Cortical area was more predictive of neuronal selectivity than laminar location or axonal projection target. Motor cortex therefore represents sensory, motor, and outcome information in a spatially organized manner. Copyright © 2017 Elsevier Inc. All rights reserved.

Reduced activation and altered laterality in two neuroleptic-naive catatonic patients during a motor task in functional MRI.

PubMed

Northoff, G; Braus, D F; Sartorius, A; Khoram-Sefat, D; Russ, M; Eckert, J; Herrig, M; Leschinger, A; Bogerts, B; Henn, F A

1999-07-01

Catatonia, a symptom complex with motor, affective and cognitive symptoms seen in a variety of psychotic conditions and with organic disease, was examined using a motor task using functional magnetic resonance imaging (fMRI). Two acute catatonic patients and two age- and sex-matched healthy controls performed sequential finger opposition (SFO) after being medicated with 2 mg of lorazepam (i.v.). Functional magnetic resonance images were collected using a gradient echo pulse sequence (EPI). Patients with catatonia showed reduced motor activation of the contralateral motor cortex during SFO of the right hand, ipsilateral activation was similar for patients and controls. There were no differences in the activation of the SMA. During left hand activation the right-handed catatonic patients showed more activation in the ipsilateral cortex, a reversal from the normal pattern of activation in which the contralateral side shows four to five times more activation than the ipsilateral side. In catatonic patients there is a decreased activation in motor cortex during a motor task compared to matched medicated healthy controls. In addition activation of the non-dominant side, left-handed activity in right-handed patients, results in a total reversal of the normal pattern of lateral activation suggesting a disturbance in hemispheric localization of activity during a catatonic state.

The quantitative assessment of motor activity in mania and schizophrenia.

PubMed

Minassian, Arpi; Henry, Brook L; Geyer, Mark A; Paulus, Martin P; Young, Jared W; Perry, William

2010-01-01

Increased motor activity is a cardinal feature of the mania of Bipolar Disorder (BD), and is thought to reflect dopaminergic dysregulation. Motor activity in BD has been studied almost exclusively with self-report and observer-rated scales, limiting the ability to objectively quantify this behavior. We used an ambulatory monitoring device to quantify motor activity in BD and schizophrenia (SCZ) patients in a novel exploratory paradigm, the human Behavioral Pattern Monitor (BPM). 28 patients in the manic phase of BD, 17 SCZ patients, and 21 nonpatient (NC) subjects were tested in the BPM, an unfamiliar room containing novel objects. Motor activity was measured with a wearable ambulatory monitoring device (LifeShirt). Manic BD patients exhibited higher levels of motor activity when exploring the novel environment than SCZ and NC groups. Motor activity showed some modest relationships with symptom ratings of mania and psychosis and was not related to smoking or body mass index. Although motor activity did not appear to be impacted significantly by antipsychotic or mood-stabilizing medications, this was a naturalistic study and medications were not controlled, thus limiting conclusions about potential medication effects on motor activity. Manic BD patients exhibit a unique signature of motoric overactivity in a novel exploratory environment. The use of an objective method to quantify exploration and motor activity may help characterize the unique aspects of BD and, because it is amenable to translational research, may further the study of the biological and genetic bases of the disease.

The effect of oral motor activity on the athletic performance of professional golfers

PubMed Central

Ringhof, Steffen; Hellmann, Daniel; Meier, Florian; Etz, Eike; Schindler, Hans J.; Stein, Thorsten

2015-01-01

Human motor control is based on complex sensorimotor processes. Recent research has shown that neuromuscular activity of the craniomandibular system (CMS) might affect human motor control. In particular, improvements in postural stability and muscle strength have been observed as a result of voluntary jaw clenching. Potential benefits of jaw aligning appliances on muscle strength and golf performance have also been described. These reports are highly contradictory, however, and the oral motor task performed is often unclear. The purpose of our study was, therefore, to investigate the effect of submaximum biting on golf performance via shot precision and shot length over three different distances. Participants were 14 male professional golfers – seven with sleep bruxism and seven without – randomly performing golf shots over 60m, 160m, or driving distance while either biting on an oral splint or biting on their teeth; habitual jaw position served as the control condition. Statistical analysis revealed that oral motor activity did not systematically affect golf performance in respect of shot precision or shot length for 60m, 160 m, or driving distance. These findings were reinforced by impact variables such as club head speed and ball speed, which were also not indicative of significant effects. The results thus showed that the strength improvements and stabilizing effects described previously are, apparently, not transferable to such coordination-demanding sports as golf. This could be due to the divergent motor demands associated with postural control and muscle strength on the one hand and the complex coordination of a golf swing on the other. Interestingly, subjects without sleep bruxism performed significantly better at the short distance (60 m) than those with bruxism. Because of the multifactorial etiology of parafunctional CMS activity, conclusions about the need for dental treatment to improve sports performance are, however, completely unwarranted. PMID

Twenty-four-hour motor activity in human infants with and without iron deficiency anemia.

PubMed

Angulo-Kinzler, R M; Peirano, P; Lin, E; Algarin, C; Garrido, M; Lozoff, B

2002-12-01

Iron deficiency anemia (IDA) is a very common nutritional problem that alters motor activity. The aim of this study was to compare 24-h motor activity in the home in healthy 6-month-old infants with and without IDA. Activity was assessed via actigraphs on the leg during 24 continuous hours in 17 Chilean infants with IDA and 18 with normal hemoglobin levels. All infants were given oral iron, and activity was reassessed at 12 and 18 months. The frequency of movement units per minute was determined for each waking/sleep state during the day and night, and the duration of each state was computed. At 6 months of age, there were no differences between anemic and nonanemic infants in time per state. However, infants with IDA showed an overall increase in motor activity compared to controls. These differences were no longer observed at 12 and 18 months of age. Increased activity during the period of IDA raises the issue of a shared underlying mechanism with restless legs syndrome, a sensorimotor dysfunction where iron deficiency increases the severity of the symptoms and iron supplementation ameliorates them. Due to previous findings of decreased motor activity in the laboratory at 12 months during the waking time surrounding an afternoon nap, we also compared those data to a nap in the home. Infants with IDA were less active in the laboratory than in the home. The home versus laboratory results suggest that contextual factors affect the motor activity of IDA infants to a larger extent than controls.

Measurement of motor disability in MPTP-treated macaques using a telemetry system for estimating circadian motor activity.

PubMed

Barcia, C; De Pablos, V; Bautista-Hernández, V; Sanchez-Bahillo, A; Fernández-Barreiro, A; Poza, M; Herrero, M T

2004-03-15

The parkinsonian symptoms of primates after MPTP exposure can be measured by several visual methods (classical motor scores). However, these methods have a subjective bias, especially as regards the evaluation of the motor activity. Computerized monitoring systems represent an unbiased method for measuring the motor disability of monkeys after MPTP administration. In this work the motor activity of monkeys before and after MPTP administration is measured and compared with the activity of a control intact group by means of a telemetry system. A pronounced decrease in motor activity was observed after MPTP administration. These results suggest the monitoring method used is suited for characterizing the motor incapacity and possible improvements following treatments to test different therapies to control Parkinson's disease in MPTP models involving primates.

Motor imagery beyond the motor repertoire: Activity in the primary visual cortex during kinesthetic motor imagery of difficult whole body movements.

PubMed

Mizuguchi, N; Nakata, H; Kanosue, K

2016-02-19

To elucidate the neural substrate associated with capabilities for kinesthetic motor imagery of difficult whole-body movements, we measured brain activity during a trial involving both kinesthetic motor imagery and action observation as well as during a trial with action observation alone. Brain activity was assessed with functional magnetic resonance imaging (fMRI). Nineteen participants imagined three types of whole-body movements with the horizontal bar: the giant swing, kip, and chin-up during action observation. No participant had previously tried to perform the giant swing. The vividness of kinesthetic motor imagery as assessed by questionnaire was highest for the chin-up, less for the kip and lowest for the giant swing. Activity in the primary visual cortex (V1) during kinesthetic motor imagery with action observation minus that during action observation alone was significantly greater in the giant swing condition than in the chin-up condition within participants. Across participants, V1 activity of kinesthetic motor imagery of the kip during action observation minus that during action observation alone was negatively correlated with vividness of the kip imagery. These results suggest that activity in V1 is dependent upon the capability of kinesthetic motor imagery for difficult whole-body movements. Since V1 activity is likely related to the creation of a visual image, we speculate that visual motor imagery is recruited unintentionally for the less vivid kinesthetic motor imagery of difficult whole-body movements. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The quantitative assessment of motor activity in mania and schizophrenia

PubMed Central

Minassian, Arpi; Henry, Brook L.; Geyer, Mark A.; Paulus, Martin P.; Young, Jared W.; Perry, William

2009-01-01

Background Increased motor activity is a cardinal feature of the mania of Bipolar Disorder (BD), and is thought to reflect dopaminergic dysregulation. Motor activity in BD has been studied almost exclusively with self-report and observer-rated scales, limiting the ability to objectively quantify this behavior. We used an ambulatory monitoring device to quantify motor activity in BD and schizophrenia (SCZ) patients in a novel exploratory paradigm, the human Behavioral Pattern Monitor (BPM). Method 28 patients in the manic phase of BD, 17 SCZ patients, and 21 nonpatient (NC) subjects were tested in the BPM, an unfamiliar room containing novel objects. Motor activity was measured with a wearable ambulatory monitoring device (LifeShirt). Results Manic BD patients exhibited higher levels of motor activity when exploring the novel environment than SCZ and NC groups. Motor activity showed some modest relationships with symptom ratings of mania and psychosis and was not related to smoking or body mass index. Limitations Although motor activity did not appear to be impacted significantly by antipsychotic or mood-stabilizing medications, this was a naturalistic study and medications were not controlled, thus limiting conclusions about potential medication effects on motor activity. Conclusion Manic BD patients exhibit a unique signature of motoric overactivity in a novel exploratory environment. The use of an objective method to quantify exploration and motor activity may help characterize the unique aspects of BD and, because it is amenable to translational research, may further the study of the biological and genetic bases of the disease. PMID:19435640

Walking the talk--speech activates the leg motor cortex.

PubMed

Liuzzi, Gianpiero; Ellger, Tanja; Flöel, Agnes; Breitenstein, Caterina; Jansen, Andreas; Knecht, Stefan

2008-09-01

Speech may have evolved from earlier modes of communication based on gestures. Consistent with such a motor theory of speech, cortical orofacial and hand motor areas are activated by both speech production and speech perception. However, the extent of speech-related activation of the motor cortex remains unclear. Therefore, we examined if reading and listening to continuous prose also activates non-brachiofacial motor representations like the leg motor cortex. We found corticospinal excitability of bilateral leg muscle representations to be enhanced by speech production and silent reading. Control experiments showed that speech production yielded stronger facilitation of the leg motor system than non-verbal tongue-mouth mobilization and silent reading more than a visuo-attentional task thus indicating speech-specificity of the effect. In the frame of the motor theory of speech this finding suggests that the system of gestural communication, from which speech may have evolved, is not confined to the hand but includes gestural movements of other body parts as well.

Motor Activity and Intra-Individual Variability According to Sleep-wake States in Preschool-aged Children with Iron-Deficiency Anemia in Infancy

PubMed Central

Angulo-Barroso, R.M.; Peirano, P.; Algarin, C.; Kaciroti, N.; Lozoff, B.

2013-01-01

Background A chronic or acute insult may affect the regulatory processes that guide motor and behavioral performance, leading to increased intra-individual variability (IIV). Increased variability is often interpreted as an indication of regulatory dysfunction. Iron plays an important role in the regulatory processes of the nervous system and affects motor activity. To our knowledge, no study has examined the long-lasting patterns and IIV of motor activity following iron-deficiency anemia in human infants. Aims This study compared 48-hour motor activity and variability in preschool-aged children with or without iron-deficiency anemia (IDA) in infancy. Methods Motor activity was recorded through actigraphs during two week-days in 47 4-year-old Chilean children (23 former IDA and 24 non-anemic in infancy). All were given oral iron as infants. Sleep-wake states were identified by means of automated software. The frequency of movement units per minute was determined for each waking/sleep state during the individual day and night periods; data were examined in blocks of 15 minutes. Analyses of mean frequency and duration and intra-individual variability were conducted using multivariate mixed models. Results For daytime sleep, former IDA children were more active without a difference in the total duration. They also spent less time awake throughout the individual day period. Motor activity intra-individual variability was higher in former IDA children. Conclusions The findings suggest that IDA in infancy sets the stage for long lasting dysfunction in the neural processes regulating sleep-wake states and spontaneous motor activity patterns. PMID:24041817

Motor activity and intra-individual variability according to sleep-wake states in preschool-aged children with iron-deficiency anemia in infancy.

PubMed

Angulo-Barroso, R M; Peirano, P; Algarin, C; Kaciroti, N; Lozoff, B

2013-12-01

A chronic or acute insult may affect the regulatory processes that guide motor and behavioral performance, leading to increased intra-individual variability (IIV). Increased variability is often interpreted as an indication of regulatory dysfunction. Iron plays an important role in the regulatory processes of the nervous system and affects motor activity. To our knowledge, no study has examined the long-lasting patterns and IIV of motor activity following iron-deficiency anemia in human infants. This study compared 48-h motor activity and variability in preschool-aged children with or without iron-deficiency anemia (IDA) in infancy. Motor activity was recorded through actigraphs during two week-days in 47 4-year-old Chilean children (23 former IDA and 24 non-anemic in infancy). All were given oral iron as infants. Sleep-wake states were identified by means of automated software. The frequency of movement units per minute was determined for each waking/sleep state during the individual day and night periods; data were examined in blocks of 15 min. Analyses of mean frequency and duration and intra-individual variability were conducted using multivariate mixed models. For daytime sleep, former IDA children were more active without a difference in the total duration. They also spent less time awake throughout the individual day period. Motor activity intra-individual variability was higher in former IDA children. The findings suggest that IDA in infancy sets the stage for long lasting dysfunction in the neural processes regulating sleep-wake states and spontaneous motor activity patterns. © 2013.

Learning to associate novel words with motor actions: language-induced motor activity following short training.

PubMed

Fargier, Raphaël; Paulignan, Yves; Boulenger, Véronique; Monaghan, Padraic; Reboul, Anne; Nazir, Tatjana A

2012-07-01

Action words referring to face, arm or leg actions activate areas along the motor strip that also control the planning and execution of the actions specified by the words. This electroencephalogram (EEG) study aimed to test the learning profile of this language-induced motor activity. Participants were trained to associate novel verbal stimuli to videos of object-oriented hand and arm movements or animated visual images on two consecutive days. Each training session was preceded and followed by a test-session with isolated videos and verbal stimuli. We measured motor-related brain activity (reflected by a desynchronization in the μ frequency bands; 8-12 Hz range) localized at centro-parietal and fronto-central electrodes. We compared activity from viewing the videos to activity resulting from processing the language stimuli only. At centro-parietal electrodes, stable action-related μ suppression was observed during viewing of videos in each test-session of the two days. For processing of verbal stimuli associated with motor actions, a similar pattern of activity was evident only in the second test-session of Day 1. Over the fronto-central regions, μ suppression was observed in the second test-session of Day 2 for the videos and in the second test-session of Day 1 for the verbal stimuli. Whereas the centro-parietal μ suppression can be attributed to motor events actually experienced during training, the fronto-central μ suppression seems to serve as a convergence zone that mediates underspecified motor information. Consequently, sensory-motor reactivations through which concepts are comprehended seem to differ in neural dynamics from those implicated in their acquisition. Copyright © 2011 Elsevier Srl. All rights reserved.

Inflammation Effects on Motivation and Motor Activity: Role of Dopamine

PubMed Central

Felger, Jennifer C; Treadway, Michael T

2017-01-01

Motivational and motor deficits are common in patients with depression and other psychiatric disorders, and are related to symptoms of anhedonia and motor retardation. These deficits in motivation and motor function are associated with alterations in corticostriatal neurocircuitry, which may reflect abnormalities in mesolimbic and mesostriatal dopamine (DA). One pathophysiologic pathway that may drive changes in DAergic corticostriatal circuitry is inflammation. Biomarkers of inflammation such as inflammatory cytokines and acute-phase proteins are reliably elevated in a significant proportion of psychiatric patients. A variety of inflammatory stimuli have been found to preferentially target basal ganglia function to lead to impaired motivation and motor activity. Findings have included inflammation-associated reductions in ventral striatal neural responses to reward anticipation, decreased DA and DA metabolites in cerebrospinal fluid, and decreased availability, and release of striatal DA, all of which correlated with symptoms of reduced motivation and/or motor retardation. Importantly, inflammation-associated symptoms are often difficult to treat, and evidence suggests that inflammation may decrease DA synthesis and availability, thus circumventing the efficacy of standard pharmacotherapies. This review will highlight the impact of administration of inflammatory stimuli on the brain in relation to motivation and motor function. Recent data demonstrating similar relationships between increased inflammation and altered DAergic corticostriatal circuitry and behavior in patients with major depressive disorder will also be presented. Finally, we will discuss the mechanisms by which inflammation affects DA neurotransmission and relevance to novel therapeutic strategies to treat reduced motivation and motor symptoms in patients with high inflammation. PMID:27480574

Primary motor cortex of the parkinsonian monkey: altered encoding of active movement

PubMed Central

Pasquereau, Benjamin; DeLong, Mahlon R.

2016-01-01

Abnormalities in the movement-related activation of the primary motor cortex (M1) are thought to be a major contributor to the motor signs of Parkinson’s disease. The existing evidence, however, variably indicates that M1 is under-activated with movement, overactivated (due to a loss of functional specificity) or activated with abnormal timing. In addition, few models consider the possibility that distinct cortical neuron subtypes may be affected differently. Those gaps in knowledge were addressed by studying the extracellular activity of antidromically-identified lamina 5b pyramidal-tract type neurons (n = 153) and intratelencephalic-type corticostriatal neurons (n = 126) in the M1 of two monkeys as they performed a step-tracking arm movement task. We compared movement-related discharge before and after the induction of parkinsonism by administration of MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) and quantified the spike rate encoding of specific kinematic parameters of movement using a generalized linear model. The fraction of M1 neurons with movement-related activity declined following MPTP but only marginally. The strength of neuronal encoding of parameters of movement was reduced markedly (mean 29% reduction in the coefficients from the generalized linear model). This relative decoupling of M1 activity from kinematics was attributable to reductions in the coefficients that estimated the spike rate encoding of movement direction (−22%), speed (−40%), acceleration (−49%) and hand position (−33%). After controlling for MPTP-induced changes in motor performance, M1 activity related to movement itself was reduced markedly (mean 36% hypoactivation). This reduced activation was strong in pyramidal tract-type neurons (−50%) but essentially absent in corticostriatal neurons. The timing of M1 activation was also abnormal, with earlier onset times, prolonged response durations, and a 43% reduction in the prevalence of movement-related changes

Motor cortex stimulation and neuropathic pain: how does motor cortex stimulation affect pain-signaling pathways?

PubMed

Kim, Jinhyung; Ryu, Sang Baek; Lee, Sung Eun; Shin, Jaewoo; Jung, Hyun Ho; Kim, Sung June; Kim, Kyung Hwan; Chang, Jin Woo

2016-03-01

Neuropathic pain is often severe. Motor cortex stimulation (MCS) is used for alleviating neuropathic pain, but the mechanism of action is still unclear. This study aimed to understand the mechanism of action of MCS by investigating pain-signaling pathways, with the expectation that MCS would regulate both descending and ascending pathways. Neuropathic pain was induced in Sprague-Dawley rats. Surface electrodes for MCS were implanted in the rats. Tactile allodynia was measured by behavioral testing to determine the effect of MCS. For the pathway study, immunohistochemistry was performed to investigate changes in c-fos and serotonin expression; micro-positron emission tomography (mPET) scanning was performed to investigate changes of glucose uptake; and extracellular electrophysiological recordings were performed to demonstrate brain activity. MCS was found to modulate c-fos and serotonin expression. In the mPET study, altered brain activity was observed in the striatum, thalamic area, and cerebellum. In the electrophysiological study, neuronal activity was increased by mechanical stimulation and suppressed by MCS. After elimination of artifacts, neuronal activity was demonstrated in the ventral posterolateral nucleus (VPL) during electrical stimulation. This neuronal activity was effectively suppressed by MCS. This study demonstrated that MCS effectively attenuated neuropathic pain. MCS modulated ascending and descending pain pathways. It regulated neuropathic pain by affecting the striatum, periaqueductal gray, cerebellum, and thalamic area, which are thought to regulate the descending pathway. MCS also appeared to suppress activation of the VPL, which is part of the ascending pathway.

Fatigue, not self-rated motor symptom severity, affects quality of life in functional motor disorders.

PubMed

Gelauff, J M; Kingma, E M; Kalkman, J S; Bezemer, R; van Engelen, B G M; Stone, J; Tijssen, M A J; Rosmalen, J G M

2018-06-02

While fatigue is found to be an impairing symptom in functional motor disorders (FMD) in clinical practice, scientific evidence is lacking. We investigated fatigue severity and subtypes in FMD compared to organic neurological disease. Furthermore, the role of fatigue within FMD and its impact on quality of life and self-rated health were investigated. Data from 181 patients participating in the self-help on the internet for functional motor disorders, randomised Trial were included. Data from 217 neurological controls with neuromuscular disorders (NMD) originated from a historical cohort. Fatigue was measured using the checklist individual strength (CIS). Motor symptom severity, depression and anxiety were correlated to fatigue. For multivariable regression analyses, physical functioning and pain were additionally taken into account. Severe fatigue was, respectively, present in 78 and 53% of FMD and NMD patients (p < 0.001). FMD patients scored higher than NMD patients on all fatigue subdomains (p < 0.001). In the FMD group, fatigue subdomains were correlated to depression, anxiety and partly to motor symptom severity. Quality of life was negatively associated with fatigue [OR 0.93 (0.90-0.96), p < 0.001] and depression [OR 0.87 (0.81-0.93), p < 0.001], but not self-rated motor symptom severity. Self-rated health was negatively associated with fatigue [OR 0.92 (0.88-0.96), p < 0.001] and pain [OR 0.98 (0.97-0.99), p < 0.001]. Fatigue was found to be a prevalent problem in FMD, more so than in organic neurological disease. It significantly affected quality of life and self-rated health, while other factors such as motor symptom severity did not. Fatigue should be taken into account in clinical practice and treatment trials.

Recruitment of rat diaphragm motor units across motor behaviors with different levels of diaphragm activation.

PubMed

Seven, Yasin B; Mantilla, Carlos B; Sieck, Gary C

2014-12-01

Phrenic motor neurons are recruited across a range of motor behaviors to generate varying levels of diaphragm muscle (DIAm) force. We hypothesized that DIAm motor units are recruited in a fixed order across a range of motor behaviors of varying force levels, consistent with the Henneman Size Principle. Single motor unit action potentials and compound DIAm EMG activities were recorded in anesthetized, neurally intact rats across different motor behaviors, i.e., eupnea, hypoxia-hypercapnia (10% O2 and 5% CO2), deep breaths, sustained airway occlusion, and sneezing. Central drive [estimated by root-mean-squared (RMS) EMG value 75 ms after the onset of EMG activity (RMS75)], recruitment delay, and onset discharge frequencies were similar during eupnea and hypoxia-hypercapnia. Compared with eupnea, central drive increased (∼25%) during deep breaths, and motor units were recruited ∼12 ms earlier (P < 0.01). During airway occlusion, central drive was ∼3 times greater, motor units were recruited ∼30 ms earlier (P < 0.01), and motor unit onset discharge frequencies were significantly higher (P < 0.01). Recruitment order of motor unit pairs observed during eupnea was maintained for 98%, 87%, and 84% of the same pairs recorded during hypoxia-hypercapnia, deep breaths, and airway occlusion, respectively. Reversals in motor unit recruitment order were observed primarily if motor unit pairs were recruited <20 ms apart. These results are consistent with DIAm motor unit recruitment order being determined primarily by the intrinsic size-dependent electrophysiological properties of phrenic motor neurons. Copyright © 2014 the American Physiological Society.

Recruitment of rat diaphragm motor units across motor behaviors with different levels of diaphragm activation

PubMed Central

Seven, Yasin B.; Mantilla, Carlos B.

2014-01-01

Phrenic motor neurons are recruited across a range of motor behaviors to generate varying levels of diaphragm muscle (DIAm) force. We hypothesized that DIAm motor units are recruited in a fixed order across a range of motor behaviors of varying force levels, consistent with the Henneman Size Principle. Single motor unit action potentials and compound DIAm EMG activities were recorded in anesthetized, neurally intact rats across different motor behaviors, i.e., eupnea, hypoxia-hypercapnia (10% O2 and 5% CO2), deep breaths, sustained airway occlusion, and sneezing. Central drive [estimated by root-mean-squared (RMS) EMG value 75 ms after the onset of EMG activity (RMS75)], recruitment delay, and onset discharge frequencies were similar during eupnea and hypoxia-hypercapnia. Compared with eupnea, central drive increased (∼25%) during deep breaths, and motor units were recruited ∼12 ms earlier (P < 0.01). During airway occlusion, central drive was ∼3 times greater, motor units were recruited ∼30 ms earlier (P < 0.01), and motor unit onset discharge frequencies were significantly higher (P < 0.01). Recruitment order of motor unit pairs observed during eupnea was maintained for 98%, 87%, and 84% of the same pairs recorded during hypoxia-hypercapnia, deep breaths, and airway occlusion, respectively. Reversals in motor unit recruitment order were observed primarily if motor unit pairs were recruited <20 ms apart. These results are consistent with DIAm motor unit recruitment order being determined primarily by the intrinsic size-dependent electrophysiological properties of phrenic motor neurons. PMID:25257864

Myosin Transducer Mutations Differentially Affect Motor Function, Myofibril Structure, and the Performance of Skeletal and Cardiac Muscles

PubMed Central

Cammarato, Anthony; Dambacher, Corey M.; Knowles, Aileen F.; Kronert, William A.; Bodmer, Rolf

2008-01-01

Striated muscle myosin is a multidomain ATP-dependent molecular motor. Alterations to various domains affect the chemomechanical properties of the motor, and they are associated with skeletal and cardiac myopathies. The myosin transducer domain is located near the nucleotide-binding site. Here, we helped define the role of the transducer by using an integrative approach to study how Drosophila melanogaster transducer mutations D45 and Mhc5 affect myosin function and skeletal and cardiac muscle structure and performance. We found D45 (A261T) myosin has depressed ATPase activity and in vitro actin motility, whereas Mhc5 (G200D) myosin has these properties enhanced. Depressed D45 myosin activity protects against age-associated dysfunction in metabolically demanding skeletal muscles. In contrast, enhanced Mhc5 myosin function allows normal skeletal myofibril assembly, but it induces degradation of the myofibrillar apparatus, probably as a result of contractile disinhibition. Analysis of beating hearts demonstrates depressed motor function evokes a dilatory response, similar to that seen with vertebrate dilated cardiomyopathy myosin mutations, and it disrupts contractile rhythmicity. Enhanced myosin performance generates a phenotype apparently analogous to that of human restrictive cardiomyopathy, possibly indicating myosin-based origins for the disease. The D45 and Mhc5 mutations illustrate the transducer's role in influencing the chemomechanical properties of myosin and produce unique pathologies in distinct muscles. Our data suggest Drosophila is a valuable system for identifying and modeling mutations analogous to those associated with specific human muscle disorders. PMID:18045988

Effect of activity-based mirror therapy on lower limb motor-recovery and gait in stroke: A randomised controlled trial.

PubMed

Arya, Kamal Narayan; Pandian, Shanta; Kumar, Vikas

2017-09-26

To determine the effect of activity-based mirror therapy (MT) on motor recovery and gait in chronic poststroke hemiparetic subjects. A randomised, controlled, assessor-blinded trial. Rehabilitation institute. Thirty-six chronic poststroke (15.89 ± 9.01 months) hemiparetic subjects (age: 46.44 ± 7.89 years, 30 men and functional ambulation classification of median level 3). Activity-based MT comprised movements such as ball-rolling, rocker-board, and pedalling. The activities were provided on the less-affected side in front of the mirror while hiding the affected limb. The movement of the less-affected lower limb was projected as over the affected limb. Conventional motor therapy based on neurophysiological approaches was also provided to the experimental group. The control group received only conventional management. Brunnstrom recovery stages (BRS), Fugl-Meyer assessment lower extremity (FMA-LE), Rivermead visual gait assessment (RVGA), and 10-metre walk test (10-MWT). Postintervention, the experimental group exhibited significant and favourable changes for FMA-LE (mean difference = 3.29, 95% CI = 1.23-5.35, p = .003) and RVGA (mean difference = 5.41, 95% CI = 1.12-9.71, p = .015) in comparison to the control group. No considerable changes were observed on 10-MWT. Activity-based MT facilitates motor recovery of the lower limb as well as reduces gait deviations among chronic poststroke hemiparetic subjects.

Dissociating motivational direction and affective valence: specific emotions alter central motor processes.

PubMed

Coombes, Stephen A; Cauraugh, James H; Janelle, Christopher M

2007-11-01

We aimed to clarify the relation between affective valence and motivational direction by specifying how central and peripheral components of extension movements are altered according to specific unpleasant affective states. As predicted, premotor reaction time was quicker for extension movements initiated during exposure to attack than for extension movements initiated during exposure to all other valence categories (mutilation, erotic couples, opposite-sex nudes, neutral humans, household objects, blank). Exposure to erotic couples and mutilations yielded greater peak force than exposure to images of attack, neutral humans, and household objects. Finally, motor reaction time and peak electromyographic amplitude were not altered by valence. These findings indicate that unpleasant states do not unilaterally prime withdrawal movements, and that the quick execution of extension movements during exposure to threatening images is due to rapid premotor, rather than motor, reaction time. Collectively, our findings support the call for dissociating motivational direction and affective valence.

Associations between gross motor skills and physical activity in Australian toddlers.

PubMed

Veldman, Sanne L C; Jones, Rachel A; Santos, Rute; Sousa-Sá, Eduarda; Pereira, João R; Zhang, Zhiguang; Okely, Anthony D

2018-08-01

Physical activity can be promoted by high levels of gross motor skills. A systematic review found a positive relationship in children (3-18 years) but only few studies examined this in younger children. The aim of this study was to examine the association between gross motor skills and physical activity in children aged 11-29 months. Cross-sectional study. This study involved 284 children from 30 childcare services in NSW, Australia (Mean age=19.77±4.18months, 53.2% boys). Physical activity was measured using accelerometers (Actigraph GT3X+). Gross motor skills were assessed using the Peabody Developmental Motor Scales Second Edition (PDMS-2). Multilevel linear regression analyses were computed to assess associations between gross motor skills and physical activity, adjusting for sex, age and BMI. Children spent 53.08% of their time in physical activity and 10.39% in moderate to vigorous physical activity (MVPA). Boys had higher total physical activity (p<0.01) and MVPA (p<0.01) than girls. The average gross motor skills score was 96.16. Boys scored higher than girls in object manipulation (p<0.001). There was no association between gross motor skills and total physical activity or MVPA. Although gross motor skills were not associated with physical activity in this sample, stronger associations are apparent in older children. This study therefore highlights a potential important age to promote gross motor skills. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Respiratory pattern in awake rats: effects of motor activity and of alerting stimuli.

PubMed

Kabir, Muammar M; Beig, Mirza I; Baumert, Mathias; Trombini, Mimosa; Mastorci, Francesca; Sgoifo, Andrea; Walker, Frederick R; Day, Trevor A; Nalivaiko, Eugene

2010-08-04

Our aim was to assess the impact of motor activity and of arousing stimuli on respiratory rate in the awake rats. The study was performed in male adult Sprague-Dawley (SD, n=5) and Hooded Wistar (HW, n=5) rats instrumented for ECG telemetry. Respiratory rate was recorded using whole-body plethysmograph, with a piezoelectric sensor attached for the simultaneous assessment of motor activity. All motor activity was found to be associated with an immediate increase in respiratory rate that remained elevated for the whole duration of movement; this was reflected by: i) bimodal distribution of respiratory intervals (modes for slow peak: 336+/-19 and 532+/-80 ms for HW and SD, p<0.05; modes for fast peak 128+/-6 and 132+/-7 ms for HW and SD, NS); and ii) a tight correlation between total movement time and total time of tachypnoea, with an R(2) ranging 0.96-0.99 (n=10, p<0001). The extent of motor-related tachypnoea was significantly correlated with the intensity of associated movement. Mild alerting stimuli produced stereotyped tachypnoeic responses, without affecting heart rate: tapping the chamber raised respiratory rate from 117+/-7 to 430+/-15 cpm; sudden side move--from 134+/-13 to 487+/-16 cpm, and turning on lights--from 136+/-12 to 507+/-14 cpm (n=10; p<0.01 for all; no inter-strain differences). We conclude that: i) sniffing is an integral part of the generalized arousal response and does not depend on the modality of sensory stimuli; ii) tachypnoea is a sensitive index of arousal; and iii) respiratory rate is tightly correlated with motor activity. Copyright 2010 Elsevier Inc. All rights reserved.

Polarity of cortical electrical stimulation differentially affects neuronal activity of deep and superficial layers of rat motor cortex.

PubMed

Yazdan-Shahmorad, Azadeh; Kipke, Daryl R; Lehmkuhle, Mark J

2011-10-01

Cortical electrical stimulation (CES) techniques are practical tools in neurorehabilitation that are currently being used to test models of functional recovery after neurologic injury. However, the mechanisms by which CES has therapeutic effects, are not fully understood. In this study, we investigated the effects of CES on unit activity of different neuronal elements in layers of rat primary motor cortex after the offset of stimulation. We evaluated the effects of monopolar CES pulse polarity (anodic-first versus cathodic-first) using various stimulation frequencies and amplitudes on unit activity after stimulation. A penetrating single shank silicon microelectrode array enabled us to span the entirety of six layer motor cortex allowing simultaneous electrophysiologic recordings from different depths after monopolar CES. Neural spiking activity before the onset and after the offset of CES was modeled using point processes fit to capture neural spiking dynamics as a function of extrinsic stimuli based on generalized linear model methods. We found that neurons in lower layers have a higher probability of being excited after anodic CES. Conversely, neurons located in upper cortical layers have a higher probability of being excited after cathodic stimulation. The opposing effects observed following anodic versus cathodic stimulation in upper and lower layers were frequency- and amplitude-dependent. The data demonstrates that the poststimulus changes in neural activity after manipulation of CES parameters changes according to the location (depth) of the recorded units in rat primary motor cortex. The most effective pulse polarity for eliciting action potentials after stimulation in lower layers was not as effective in upper layers. Likewise, lower amplitudes and frequencies of CES were more effective than higher amplitudes and frequencies for eliciting action potentials. These results have important implications in the context of maximizing efficacy of CES for

Differential activation in the primary motor cortex during individual digit movement in focal hand dystonia vs. healthy.

PubMed

Kimberley, Teresa J; Pickett, Kristen A

2012-01-01

The pathophysiology of focal hand dystonia (FHD) is not clearly understood. Previous studies have reported increased and decreased cortical activity associated with motor tasks. The aim of this study was to investigate blood oxygen level dependent (BOLD) signal changes in functional magnetic resonance imaging within the hand area of primary motor cortex during cued movement of individual digits. Eight healthy individuals and five individuals with right hand FHD participated. Beta weight contrasts were examined within the hand area of the motor cortex. In both groups, BOLD signal changes in the hemisphere contralateral to the moving hand were greater in the left hemisphere than the right. Between groups, no difference was found during control of the left hand, but a significant difference was seen during right hand movement; specifically, individuals with dystonia showed increased contralateral and decreased ipsilateral cortical response associated with the affected hand as compared to healthy individuals. This suggests a similar, albeit exaggerated pattern of activation in individuals with FHD on the affected side. These results suggest different levels of ipsilateral and contralateral activation between healthy and dystonic individuals but also show a relative difference between symptomatic and asymptomatic control within the patient population.

Actigraphy--a useful tool for motor activity monitoring in stroke patients.

PubMed

Reiterer, Veronika; Sauter, Cornelia; Klösch, Gerhard; Lalouschek, Wolfgang; Zeitlhofer, Josef

2008-01-01

The aim of the present study was the evaluation of actigraphy as a tool to objectify the recovery process after motor paresis due to stroke. The motor activity of both arms of patients suffering from stroke was actigraphically recorded at four different time points during the course of rehabilitation: 24-36 h, 5-7 days, 3 months, and 6 months after stroke. Motor activity monitored by wrist-worn actigraphs located at the impaired side revealed an increase in activity between the first two time points and the subsequent ones. Additionally, actigraphic recordings showed lower total motor activity at the impaired side as compared to the nonimpaired side. A significant positive correlation was found between the actigraphically recorded motor activity and the results of the Scandinavian Stroke scale, the Barthel Index, the Rankin Scale Score and with the Motoricity Index during the 1st week, which corresponds to the time when neurological deficits were most pronounced. Our results suggest that actigraphy is a useful tool in the objective evaluation of motor activity after stroke. Moreover, actigraphy covers additional aspects that are not reflected by the usual stroke scales in a clinical situation. Copyright 2008 S. Karger AG, Basel.

Actigraphic motor activity during sleep from infancy to adulthood.

PubMed

Tonetti, Lorenzo; Scher, Anat; Atun-Einy, Osnat; Samuel, Moran; Boreggiani, Michele; Natale, Vincenzo

2017-01-01

A secondary analysis of longitudinal and cohort studies was carried out to quantitatively investigate the motor activity pattern, recorded through actigraphy, during the first six hours of nocturnal sleep. The first study was of longitudinal nature. Ten healthy participants (four females) were monitored three times, at baseline (T1) when they were infants (mean age 7.10 ± 0.32 months), at the first follow-up examination (T2) around 4 months later (mean age 11.20 ± 0.63 months) and at the second follow-up (T3) around three years later, when they were preschoolers (mean age 4.68 ± 0.14 years). At T1, T2 and T3 each participant wore the actigraph Basic Mini-Motionlogger (Ambulatory Monitoring, Inc., Ardsley, NY, USA) over at least two consecutive nycthemeral cycles, with the aim to measure the mean hourly motor activity count. Seven- and 11-month-old infants had a higher level of motor activity over the night compared to preschoolers. Furthermore, motor activity increased as the night progressed, with a pronounced increment at both T1 and T2, while at T3 such an increase was less marked. The second study was cross-sectional and aimed to explore the motor activity pattern, using actigraphy, during the first six hours of nocturnal sleep in multiple-age healthy groups, from infancy to adulthood. We assigned participants to eight groups according to age: 20 (five females) aged around 10 months old (mean age 10.65 ± 0.67 months); 13 (nine females) aged around 4 years (mean age 4.38 ± 0.51 years); 21 (10 females) aged around 10 years (mean age 9.67 ± 0.91 years); 21 (nine females) aged around 20 years (mean age 19.33 ± 2.44 years); 20 (10 females) aged around 30 years (mean age 29.80 ± 1.99 years); 20 (15 females) aged around 40 years (mean age 40.70 ± 1.26 years); 20 (11 females) aged around 50 years (mean age 50.15 ± 2.80 years) and 20 (nine females) aged around 60 years (mean age 59.25 ± 3.23 years). The participants aged between 10 and 60 years wore the

Mechanism of gastrointestinal abnormal motor activity induced by cisplatin in conscious dogs.

PubMed

Ando, Hiroyuki; Mochiki, Erito; Ohno, Tetsuro; Yanai, Mitsuhiro; Toyomasu, Yoshitaka; Ogata, Kyoichi; Tabe, Yuichi; Aihara, Ryuusuke; Nakabayashi, Toshihiro; Asao, Takayuki; Kuwano, Hiroyuki

2014-11-14

To investigate whether 5-hydroxytryptamine (serotonin; 5-HT) is involved in mediating abnormal motor activity in dogs after cisplatin administration. After the dogs had been given a 2-wk recovery period, all of them were administered cisplatin, and the motor activity was recorded using strain gauge force transducers. Blood and intestinal fluid samples were collected to measure 5-HT for 24 h. To determine whether 5-HT in plasma or that in intestinal fluids is more closely related to abnormal motor activity we injected 5-HT into the bloodstream and the intestinal tract of the dogs. Cisplatin given intravenously produced abnormal motor activity that lasted up to 5 h. From 3 to 4 h after cisplatin administration, normal intact dogs exhibited retropropagation of motor activity accompanied by emesis. The concentration of 5-HT in plasma reached the peak at 4 h, and that in intestinal fluids reached the peak at 3 h. In normal intact dogs with resection of the vagus nerve that were administered kytril, cisplatin given intravenously did not produce abnormal motor activity. Intestinal serotonin administration did not produce abnormal motor activity, but intravenous serotonin administration did. After the intravenous administration of cisplatin, abnormal motor activity was produced in the involved vagus nerve and in the involved serotonergic neurons via another pathway. This study was the first to determine the relationship between 5-HT and emesis-induced motor activity.

Ambulatory monitoring of activities and motor symptoms in Parkinson's disease.

PubMed

Zwartjes, Daphne G M; Heida, Tjitske; van Vugt, Jeroen P P; Geelen, Jan A G; Veltink, Peter H

2010-11-01

Ambulatory monitoring of motor symptoms in Parkinsons disease (PD) can improve our therapeutic strategies, especially in patients with motor fluctuations. Previously published monitors usually assess only one or a few basic aspects of the cardinal motor symptoms in a laboratory setting. We developed a novel ambulatory monitoring system that provides a complete motor assessment by simultaneously analyzing current motor activity of the patient (e.g. sitting, walking) and the severity of many aspects related to tremor, bradykinesia, and hypokinesia. The monitor consists of a set of four inertial sensors. Validity of our monitor was established in seven healthy controls and six PD patients treated with deep brain stimulation (DBS) of the subthalamic nucleus. Patients were tested at three different levels of DBS treatment. Subjects were monitored while performing different tasks, including motor tests of the Unified Parkinsons Disease Rating Scale (UPDRS). Output of the monitor was compared to simultaneously recorded videos. The monitor proved very accurate in discriminating between several motor activities. Monitor output correlated well with blinded UPDRS ratings during different DBS levels. The combined analysis of motor activity and symptom severity by our PD monitor brings true ambulatory monitoring of a wide variety of motor symptoms one step closer..

Brain Activation in Primary Motor and Somatosensory Cortices during Motor Imagery Correlates with Motor Imagery Ability in Stroke Patients

PubMed Central

Confalonieri, Linda; Pagnoni, Giuseppe; Barsalou, Lawrence W.; Rajendra, Justin; Eickhoff, Simon B.; Butler, Andrew J.

2012-01-01

Aims. While studies on healthy subjects have shown a partial overlap between the motor execution and motor imagery neural circuits, few have investigated brain activity during motor imagery in stroke patients with hemiparesis. This work is aimed at examining similarities between motor imagery and execution in a group of stroke patients. Materials and Methods. Eleven patients were asked to perform a visuomotor tracking task by either physically or mentally tracking a sine wave force target using their thumb and index finger during fMRI scanning. MIQ-RS questionnaire has been administered. Results and Conclusion. Whole-brain analyses confirmed shared neural substrates between motor imagery and motor execution in bilateral premotor cortex, SMA, and in the contralesional inferior parietal lobule. Additional region of interest-based analyses revealed a negative correlation between kinaesthetic imagery ability and percentage BOLD change in areas 4p and 3a; higher imagery ability was associated with negative and lower percentage BOLD change in primary sensorimotor areas during motor imagery. PMID:23378930

Motor Neurons Tune Premotor Activity in a Vertebrate Central Pattern Generator

PubMed Central

2017-01-01

Central patterns generators (CPGs) are neural circuits that drive rhythmic motor output without sensory feedback. Vertebrate CPGs are generally believed to operate in a top-down manner in which premotor interneurons activate motor neurons that in turn drive muscles. In contrast, the frog (Xenopus laevis) vocal CPG contains a functionally unexplored neuronal projection from the motor nucleus to the premotor nucleus, indicating a recurrent pathway that may contribute to rhythm generation. In this study, we characterized the function of this bottom-up connection. The X. laevis vocal CPG produces a 50–60 Hz “fast trill” song used by males during courtship. We recorded “fictive vocalizations” in the in vitro CPG from the laryngeal nerve while simultaneously recording premotor activity at the population and single-cell level. We show that transecting the motor-to-premotor projection eliminated the characteristic firing rate of premotor neurons. Silencing motor neurons with the intracellular sodium channel blocker QX-314 also disrupted premotor rhythms, as did blockade of nicotinic synapses in the motor nucleus (the putative location of motor neuron-to-interneuron connections). Electrically stimulating the laryngeal nerve elicited primarily IPSPs in premotor neurons that could be blocked by a nicotinic receptor antagonist. Our results indicate that an inhibitory signal, activated by motor neurons, is required for proper CPG function. To our knowledge, these findings represent the first example of a CPG in which precise premotor rhythms are tuned by motor neuron activity. SIGNIFICANCE STATEMENT Central pattern generators (CPGs) are neural circuits that produce rhythmic behaviors. In vertebrates, motor neurons are not commonly known to contribute to CPG function, with the exception of a few spinal circuits where the functional significance of motor neuron feedback is still poorly understood. The frog hindbrain vocal circuit contains a previously unexplored

Mechanism of gastrointestinal abnormal motor activity induced by cisplatin in conscious dogs

PubMed Central

Ando, Hiroyuki; Mochiki, Erito; Ohno, Tetsuro; Yanai, Mitsuhiro; Toyomasu, Yoshitaka; Ogata, Kyoichi; Tabe, Yuichi; Aihara, Ryuusuke; Nakabayashi, Toshihiro; Asao, Takayuki; Kuwano, Hiroyuki

2014-01-01

AIM: To investigate whether 5-hydroxytryptamine (serotonin; 5-HT) is involved in mediating abnormal motor activity in dogs after cisplatin administration. METHODS: After the dogs had been given a 2-wk recovery period, all of them were administered cisplatin, and the motor activity was recorded using strain gauge force transducers. Blood and intestinal fluid samples were collected to measure 5-HT for 24 h. To determine whether 5-HT in plasma or that in intestinal fluids is more closely related to abnormal motor activity we injected 5-HT into the bloodstream and the intestinal tract of the dogs. RESULTS: Cisplatin given intravenously produced abnormal motor activity that lasted up to 5 h. From 3 to 4 h after cisplatin administration, normal intact dogs exhibited retropropagation of motor activity accompanied by emesis. The concentration of 5-HT in plasma reached the peak at 4 h, and that in intestinal fluids reached the peak at 3 h. In normal intact dogs with resection of the vagus nerve that were administered kytril, cisplatin given intravenously did not produce abnormal motor activity. Intestinal serotonin administration did not produce abnormal motor activity, but intravenous serotonin administration did. CONCLUSION: After the intravenous administration of cisplatin, abnormal motor activity was produced in the involved vagus nerve and in the involved serotonergic neurons via another pathway. This study was the first to determine the relationship between 5-HT and emesis-induced motor activity. PMID:25400453

Blood Oxygenation Level-Dependent Functional Magnetic Resonance Imaging in Early Days: Correlation between Passive Activation and Motor Recovery After Unilateral Striatocapsular Cerebral Infarction.

PubMed

Zhou, Long-Jiang; Wang, Wei; Zhao, Yi; Liu, Chun-Feng; Zhang, Xin-Jiang; Liu, Zhen-Sheng; Li, Hua-Dong

2017-11-01

This study aimed to investigate the correlation between the functional magnetic resonance imaging (fMRI) pattern and the motor function recovery of an affected limb during the passive movement of the affected limb at an early stage of the striatocapsular infarction (SCI). A total of 17 patients with an acute stage of SCI and 3 healthy volunteers as controls were included in this study. fMRI scans of passive movement were performed on the affected limbs of stroke patients within 1 week of onset. Follow-ups were carried out for the motor functions of the affected limbs (before fMRI scan, 1 month, and 3 months after the scan). The control group showed that the activation was mainly located in the contralateral sensorimotor cortex (SMC) and the bilateral supplementary motor area (SMA). The fMRI scan region of interest for stroke patients can be divided into 3 types: type I includes mainly the affected side, bilateral SMC, and SMA with activation; type II includes SMC on the affected side and SMA with activation; type III includes only SMC on the affected side or M1 with activation. The recovery of type I patients was better and faster, while the recovery of type II patients was better but slower, but recovery of type III patients was poorer and slower. Multiple cortical activation patterns were noted during the passive movement of the affected limbs at an early stage of SCI, and a correlation was found between the different activation patterns and the clinical prognosis of patients. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Motor unit activity after eccentric exercise and muscle damage in humans.

PubMed

Semmler, J G

2014-04-01

It is well known that unaccustomed eccentric exercise leads to muscle damage and soreness, which can produce long-lasting effects on muscle function. How this muscle damage influences muscle activation is poorly understood. The purpose of this brief review is to highlight the effect of eccentric exercise on the activation of muscle by the nervous system, by examining the change in motor unit activity obtained from surface electromyography (EMG) and intramuscular recordings. Previous research shows that eccentric exercise produces unusual changes in the EMG–force relation that influences motor performance during isometric, shortening and lengthening muscle contractions and during fatiguing tasks. When examining the effect of eccentric exercise at the single motor unit level, there are substantial changes in recruitment thresholds, discharge rates, motor unit conduction velocities and synchronization, which can last for up to 1 week after eccentric exercise. Examining the time course of these changes suggests that the increased submaximal EMG after eccentric exercise most likely occurs through a decrease in motor unit conduction velocity and an increase in motor unit activity related to antagonist muscle coactivation and low-frequency fatigue. Furthermore, there is a commonly held view that eccentric exercise produces preferential damage to high-threshold motor units, but the evidence for this in humans is limited. Further research is needed to establish whether there is preferential damage to high-threshold motor units after eccentric exercise in humans, preferably by linking changes in motor unit activity with estimates of motor unit size using selective intramuscular recording techniques.

Associations among Elementary School Children's Actual Motor Competence, Perceived Motor Competence, Physical Activity and BMI: A Cross-Sectional Study.

PubMed

De Meester, An; Stodden, David; Brian, Ali; True, Larissa; Cardon, Greet; Tallir, Isabel; Haerens, Leen

2016-01-01

Positive associations between motor competence and physical activity have been identified by means of variable-centered analyses. To expand the understanding of these associations, this study used a person-centered approach to investigate whether different combinations (i.e., profiles) of actual and perceived motor competence exist (aim 1); and to examine differences in physical activity levels (aim 2) and weight status (aim 3) among children with different motor competence-based profiles. Children's (N = 361; 180 boys = 50%; Mage = 9.50±1.24yrs) actual motor competence was measured with the Test of Gross Motor Development-2 and their perceived motor competence via the Self Perception Profile for Children. We assessed physical activity via accelerometers; height through stadiometers, and weight through scales. Cluster analyses (aim 1) and MANCOVAs (aim 2 & 3) were used to analyze the data. The analysis generated two predictable groups: one group displaying relatively high levels of both actual (M TGMD-2 percentile = 42.54, SD = 2.33) and perceived motor competence (M = 3.42, SD = .37; high-high), and one group with relatively low levels of both (M percentile = 9.71, SD = 3.21; M PMC = 2.52, SD = .35; low-low). One additional group was also identified as having relatively low levels of actual motor competence (M percentile = 4.22, SD = 2.85) but relatively high levels of perceived motor competence (M = 3.52, SD = .30; low-high). The high-high group demonstrated higher daily physical activity (M = 48.39±2.03) and lower BMI (M = 18.13±.43) than the low-low group (MMVPA = 37.93±2.01; MBMI = 20.22±.42). The low-high group had similar physical activity-levels as the low-low group (M = 36.21±2.18) and did not significantly differ in BMI (M = 19.49±.46) from the other two groups. A combination of high actual and perceived motor competence is related to higher physical activity and lower weight status. It is thus recommended to expand health interventions in children

Compensatory premotor activity during affective face processing in subclinical carriers of a single mutant Parkin allele.

PubMed

Anders, Silke; Sack, Benjamin; Pohl, Anna; Münte, Thomas; Pramstaller, Peter; Klein, Christine; Binkofski, Ferdinand

2012-04-01

Patients with Parkinson's disease suffer from significant motor impairments and accompanying cognitive and affective dysfunction due to progressive disturbances of basal ganglia-cortical gating loops. Parkinson's disease has a long presymptomatic stage, which indicates a substantial capacity of the human brain to compensate for dopaminergic nerve degeneration before clinical manifestation of the disease. Neuroimaging studies provide evidence that increased motor-related cortical activity can compensate for progressive dopaminergic nerve degeneration in carriers of a single mutant Parkin or PINK1 gene, who show a mild but significant reduction of dopamine metabolism in the basal ganglia in the complete absence of clinical motor signs. However, it is currently unknown whether similar compensatory mechanisms are effective in non-motor basal ganglia-cortical gating loops. Here, we ask whether asymptomatic Parkin mutation carriers show altered patterns of brain activity during processing of facial gestures, and whether this might compensate for latent facial emotion recognition deficits. Current theories in social neuroscience assume that execution and perception of facial gestures are linked by a special class of visuomotor neurons ('mirror neurons') in the ventrolateral premotor cortex/pars opercularis of the inferior frontal gyrus (Brodmann area 44/6). We hypothesized that asymptomatic Parkin mutation carriers would show increased activity in this area during processing of affective facial gestures, replicating the compensatory motor effects that have previously been observed in these individuals. Additionally, Parkin mutation carriers might show altered activity in other basal ganglia-cortical gating loops. Eight asymptomatic heterozygous Parkin mutation carriers and eight matched controls underwent functional magnetic resonance imaging and a subsequent facial emotion recognition task. As predicted, Parkin mutation carriers showed significantly stronger activity in

Compensatory premotor activity during affective face processing in subclinical carriers of a single mutant Parkin allele

PubMed Central

Sack, Benjamin; Pohl, Anna; Münte, Thomas; Pramstaller, Peter; Klein, Christine; Binkofski, Ferdinand

2012-01-01

Patients with Parkinson's disease suffer from significant motor impairments and accompanying cognitive and affective dysfunction due to progressive disturbances of basal ganglia–cortical gating loops. Parkinson's disease has a long presymptomatic stage, which indicates a substantial capacity of the human brain to compensate for dopaminergic nerve degeneration before clinical manifestation of the disease. Neuroimaging studies provide evidence that increased motor-related cortical activity can compensate for progressive dopaminergic nerve degeneration in carriers of a single mutant Parkin or PINK1 gene, who show a mild but significant reduction of dopamine metabolism in the basal ganglia in the complete absence of clinical motor signs. However, it is currently unknown whether similar compensatory mechanisms are effective in non-motor basal ganglia–cortical gating loops. Here, we ask whether asymptomatic Parkin mutation carriers show altered patterns of brain activity during processing of facial gestures, and whether this might compensate for latent facial emotion recognition deficits. Current theories in social neuroscience assume that execution and perception of facial gestures are linked by a special class of visuomotor neurons (‘mirror neurons’) in the ventrolateral premotor cortex/pars opercularis of the inferior frontal gyrus (Brodmann area 44/6). We hypothesized that asymptomatic Parkin mutation carriers would show increased activity in this area during processing of affective facial gestures, replicating the compensatory motor effects that have previously been observed in these individuals. Additionally, Parkin mutation carriers might show altered activity in other basal ganglia–cortical gating loops. Eight asymptomatic heterozygous Parkin mutation carriers and eight matched controls underwent functional magnetic resonance imaging and a subsequent facial emotion recognition task. As predicted, Parkin mutation carriers showed significantly stronger

The influence of moving with music on motor cortical activity.

PubMed

Stegemöller, Elizabeth L; Izbicki, Patricia; Hibbing, Paul

2018-06-19

Although there is a growing interest in using music to improve movement performance in various populations, there remains a need to better understand how music influences motor cortical activity. Listening to music is tightly linked to neural processes within the motor cortex and can modulate motor cortical activity in healthy young adult (HYAs). There is limited evidence regarding how moving to music modulates motor cortical activity. Thus, the purpose of this study was to explore the influence of moving to music on motor cortical activity in HYAs. Electroencephalography was collected while 32 HYAs tapped their index finger in time with a tone and with two contrasting music styles. Two movement rates were presented for each condition. Power spectra were obtained from data collected over the primary sensorimotor region and supplemental motor area and were compared between conditions. Results revealed a significant difference between both music conditions and the tone only condition for both the regions. For both music styles, power was increased in the beta band for low movement rates and increased in the alpha band for high movement rates. A secondary analysis determining the effect of music experience on motor cortical activity revealed a significant difference between musicians and non-musicians. Power in the beta band was increased across all conditions. The results of this study provide the initial step towards a more complete understanding of the neurophysiological underpinnings of music on movement performance which may inform future studies and therapeutic strategies. Copyright © 2018 Elsevier B.V. All rights reserved.

Beta-band activity and connectivity in sensorimotor and parietal cortex are important for accurate motor performance.

PubMed

Chung, Jae W; Ofori, Edward; Misra, Gaurav; Hess, Christopher W; Vaillancourt, David E

2017-01-01

Accurate motor performance may depend on the scaling of distinct oscillatory activity within the motor cortex and effective neural communication between the motor cortex and other brain areas. Oscillatory activity within the beta-band (13-30Hz) has been suggested to provide distinct functional roles for attention and sensorimotor control, yet it remains unclear how beta-band and other oscillatory activity within and between cortical regions is coordinated to enhance motor performance. We explore this open issue by simultaneously measuring high-density cortical activity and elbow flexor and extensor neuromuscular activity during ballistic movements, and manipulating error using high and low visual gain across three target distances. Compared with low visual gain, high visual gain decreased movement errors at each distance. Group analyses in 3D source-space revealed increased theta-, alpha-, and beta-band desynchronization of the contralateral motor cortex and medial parietal cortex in high visual gain conditions and this corresponded to reduced movement error. Dynamic causal modeling was used to compute connectivity between motor cortex and parietal cortex. Analyses revealed that gain affected the directionally-specific connectivity across broadband frequencies from parietal to sensorimotor cortex but not from sensorimotor cortex to parietal cortex. These new findings provide support for the interpretation that broad-band oscillations in theta, alpha, and beta frequency bands within sensorimotor and parietal cortex coordinate to facilitate accurate upper limb movement. Our findings establish a link between sensorimotor oscillations in the context of online motor performance in common source space across subjects. Specifically, the extent and distinct role of medial parietal cortex to sensorimotor beta connectivity and local domain broadband activity combine in a time and frequency manner to assist ballistic movements. These findings can serve as a model to examine

Physical activity, motor function, and white matter hyperintensity burden in healthy older adults.

PubMed

Fleischman, Debra A; Yang, Jingyun; Arfanakis, Konstantinos; Arvanitakis, Zoe; Leurgans, Sue E; Turner, Arlener D; Barnes, Lisa L; Bennett, David A; Buchman, Aron S

2015-03-31

To test the hypothesis that physical activity modifies the association between white matter hyperintensity (WMH) burden and motor function in healthy older persons without dementia. Total daily activity (exercise and nonexercise physical activity) was measured for up to 11 days with actigraphy (Actical; Philips Respironics, Bend, OR) in 167 older adults without dementia participating in the Rush Memory and Aging Project. Eleven motor performances were summarized into a previously described global motor score. WMH volume was expressed as percent of intracranial volume. Linear regression models, adjusted for age, education, and sex, were performed with total WMH volume as the predictor and global motor score as the outcome. Terms for total daily physical activity and its interaction with WMH volume were then added to the model. Higher WMH burden was associated with lower motor function (p = 0.006), and total daily activity was positively associated with motor function (p = 0.002). Total daily activity modified the association between WMH and motor function (p = 0.007). WMH burden was not associated with motor function in persons with high activity (90th percentile). By contrast, higher WMH burden remained associated with lower motor function in persons with average (50th percentile; estimate = -0.304, slope = -0.133) and low (10th percentile; estimate = -1.793, slope = -0.241) activity. Higher levels of physical activity may reduce the effect of WMH burden on motor function in healthy older adults. © 2015 American Academy of Neurology.

Physical activity, motor function, and white matter hyperintensity burden in healthy older adults

PubMed Central

Yang, Jingyun; Arfanakis, Konstantinos; Arvanitakis, Zoe; Leurgans, Sue E.; Turner, Arlener D.; Barnes, Lisa L.; Bennett, David A.; Buchman, Aron S.

2015-01-01

Objective: To test the hypothesis that physical activity modifies the association between white matter hyperintensity (WMH) burden and motor function in healthy older persons without dementia. Methods: Total daily activity (exercise and nonexercise physical activity) was measured for up to 11 days with actigraphy (Actical; Philips Respironics, Bend, OR) in 167 older adults without dementia participating in the Rush Memory and Aging Project. Eleven motor performances were summarized into a previously described global motor score. WMH volume was expressed as percent of intracranial volume. Linear regression models, adjusted for age, education, and sex, were performed with total WMH volume as the predictor and global motor score as the outcome. Terms for total daily physical activity and its interaction with WMH volume were then added to the model. Results: Higher WMH burden was associated with lower motor function (p = 0.006), and total daily activity was positively associated with motor function (p = 0.002). Total daily activity modified the association between WMH and motor function (p = 0.007). WMH burden was not associated with motor function in persons with high activity (90th percentile). By contrast, higher WMH burden remained associated with lower motor function in persons with average (50th percentile; estimate = −0.304, slope = −0.133) and low (10th percentile; estimate = −1.793, slope = −0.241) activity. Conclusions: Higher levels of physical activity may reduce the effect of WMH burden on motor function in healthy older adults. PMID:25762710

Motor-sensory confluence in tactile perception.

PubMed

Saig, Avraham; Gordon, Goren; Assa, Eldad; Arieli, Amos; Ahissar, Ehud

2012-10-03

Perception involves motor control of sensory organs. However, the dynamics underlying emergence of perception from motor-sensory interactions are not yet known. Two extreme possibilities are as follows: (1) motor and sensory signals interact within an open-loop scheme in which motor signals determine sensory sampling but are not affected by sensory processing and (2) motor and sensory signals are affected by each other within a closed-loop scheme. We studied the scheme of motor-sensory interactions in humans using a novel object localization task that enabled monitoring the relevant overt motor and sensory variables. We found that motor variables were dynamically controlled within each perceptual trial, such that they gradually converged to steady values. Training on this task resulted in improvement in perceptual acuity, which was achieved solely by changes in motor variables, without any change in the acuity of sensory readout. The within-trial dynamics is captured by a hierarchical closed-loop model in which lower loops actively maintain constant sensory coding, and higher loops maintain constant sensory update flow. These findings demonstrate interchangeability of motor and sensory variables in perception, motor convergence during perception, and a consistent hierarchical closed-loop perceptual model.

Emotional stimuli and motor conversion disorder.

PubMed

Voon, Valerie; Brezing, Christina; Gallea, Cecile; Ameli, Rezvan; Roelofs, Karin; LaFrance, W Curt; Hallett, Mark

2010-05-01

Conversion disorder is characterized by neurological signs and symptoms related to an underlying psychological issue. Amygdala activity to affective stimuli is well characterized in healthy volunteers with greater amygdala activity to both negative and positive stimuli relative to neutral stimuli, and greater activity to negative relative to positive stimuli. We investigated the relationship between conversion disorder and affect by assessing amygdala activity to affective stimuli. We conducted a functional magnetic resonance imaging study using a block design incidental affective task with fearful, happy and neutral face stimuli and compared valence contrasts between 16 patients with conversion disorder and 16 age- and gender-matched healthy volunteers. The patients with conversion disorder had positive movements such as tremor, dystonia or gait abnormalities. We also assessed functional connectivity between the amygdala and regions associated with motor preparation. A group by affect valence interaction was observed. Post hoc analyses revealed that whereas healthy volunteers had greater right amygdala activity to fearful versus neutral compared with happy versus neutral as expected, there were no valence differences in patients with conversion disorder. There were no group differences observed. The time course analysis also revealed greater right amygdala activity in patients with conversion disorder for happy stimuli (t = 2.96, P = 0.006) (with a trend for fearful stimuli, t = 1.81, P = 0.08) compared with healthy volunteers, with a pattern suggestive of impaired amygdala habituation even when controlling for depressive and anxiety symptoms. Using psychophysiological interaction analysis, patients with conversion disorder had greater functional connectivity between the right amygdala and the right supplementary motor area during both fearful versus neutral, and happy versus neutral 'stimuli' compared with healthy volunteers. These results were confirmed with

Motor-Enriched Learning Activities Can Improve Mathematical Performance in Preadolescent Children.

PubMed

Beck, Mikkel M; Lind, Rune R; Geertsen, Svend S; Ritz, Christian; Lundbye-Jensen, Jesper; Wienecke, Jacob

2016-01-01

Objective: An emerging field of research indicates that physical activity can benefit cognitive functions and academic achievements in children. However, less is known about how academic achievements can benefit from specific types of motor activities (e.g., fine and gross) integrated into learning activities. Thus, the aim of this study was to investigate whether fine or gross motor activity integrated into math lessons (i.e., motor-enrichment) could improve children's mathematical performance. Methods: A 6-week within school cluster-randomized intervention study investigated the effects of motor-enriched mathematical teaching in Danish preadolescent children ( n = 165, age = 7.5 ± 0.02 years). Three groups were included: a control group (CON), which received non-motor enriched conventional mathematical teaching, a fine motor math group (FMM) and a gross motor math group (GMM), which received mathematical teaching enriched with fine and gross motor activity, respectively. The children were tested before (T0), immediately after (T1) and 8 weeks after the intervention (T2). A standardized mathematical test (50 tasks) was used to evaluate mathematical performance. Furthermore, it was investigated whether motor-enriched math was accompanied by different effects in low and normal math performers. Additionally, the study investigated the potential contribution of cognitive functions and motor skills on mathematical performance. Results: All groups improved their mathematical performance from T0 to T1. However, from T0 to T1, the improvement was significantly greater in GMM compared to FMM (1.87 ± 0.71 correct answers) ( p = 0.02). At T2 no significant differences in mathematical performance were observed. A subgroup analysis revealed that normal math-performers benefitted from GMM compared to both CON 1.78 ± 0.73 correct answers ( p = 0.04) and FMM 2.14 ± 0.72 correct answers ( p = 0.008). These effects were not observed in low math-performers. The effects were

Motor-Enriched Learning Activities Can Improve Mathematical Performance in Preadolescent Children

PubMed Central

Beck, Mikkel M.; Lind, Rune R.; Geertsen, Svend S.; Ritz, Christian; Lundbye-Jensen, Jesper; Wienecke, Jacob

2016-01-01

Objective: An emerging field of research indicates that physical activity can benefit cognitive functions and academic achievements in children. However, less is known about how academic achievements can benefit from specific types of motor activities (e.g., fine and gross) integrated into learning activities. Thus, the aim of this study was to investigate whether fine or gross motor activity integrated into math lessons (i.e., motor-enrichment) could improve children's mathematical performance. Methods: A 6-week within school cluster-randomized intervention study investigated the effects of motor-enriched mathematical teaching in Danish preadolescent children (n = 165, age = 7.5 ± 0.02 years). Three groups were included: a control group (CON), which received non-motor enriched conventional mathematical teaching, a fine motor math group (FMM) and a gross motor math group (GMM), which received mathematical teaching enriched with fine and gross motor activity, respectively. The children were tested before (T0), immediately after (T1) and 8 weeks after the intervention (T2). A standardized mathematical test (50 tasks) was used to evaluate mathematical performance. Furthermore, it was investigated whether motor-enriched math was accompanied by different effects in low and normal math performers. Additionally, the study investigated the potential contribution of cognitive functions and motor skills on mathematical performance. Results: All groups improved their mathematical performance from T0 to T1. However, from T0 to T1, the improvement was significantly greater in GMM compared to FMM (1.87 ± 0.71 correct answers) (p = 0.02). At T2 no significant differences in mathematical performance were observed. A subgroup analysis revealed that normal math-performers benefitted from GMM compared to both CON 1.78 ± 0.73 correct answers (p = 0.04) and FMM 2.14 ± 0.72 correct answers (p = 0.008). These effects were not observed in low math-performers. The effects were partly

Affective status in relation to impulsive, motor and motivational symptoms: personality, development and physical exercise.

PubMed

Palomo, Tomas; Beninger, Richard J; Kostrzewa, Richard M; Archer, Trevor

2008-10-01

The contributions of impulsive and risk-taking behaviour in depressive and bipolar disorders, motivational and motor behaviours in anhedonic and substance addictive states, and the factors, particularly distress and trauma, underlying the development of neuropathology in affective status are described from clinical, epidemiological and laboratory perspectives. In order to distinguish one case factor for biopsychological substrates of health, an array of self-reported characteristics, e.g., positive or negative affect, stress or energy, optimism, etc., that may be predictive or counterpredictive for the propensity for physical exercise and activity were analysed using a linear regression in twelve different studies. Several individual characteristics were found to be markedly and significantly predictive of the exercise propensity, i.e., positive affect, energy, health-seeking behaviour and character, while optimism was of lesser, though significant, importance. Several individual characteristics were found to be significantly counterpredictive: expression of BDI- and HAD-depression, major sleep problems and lack/negligence of health-seeking behaviour. The consequences of physical activity and exercise for both affective well-being, cognitive mobility and neurogenesis is noted, particularly with regard to developmental assets for younger individuals. Affective disorder states may be studied through analyses of personal characteristics that unfold predispositions for symptoms-profiles and biomarkers derived from properties of dysfunction, such as impulsiveness, temperament dimensions, anhedonia and 'over-sensitivity', whether interpersonal or to reward.

Reduction of EEG Theta Power and Changes in Motor Activity in Rats Treated with Ceftriaxone

PubMed Central

Bellesi, Michele; Vyazovskiy, Vladyslav V.; Tononi, Giulio; Cirelli, Chiara; Conti, Fiorenzo

2012-01-01

The glutamate transporter GLT-1 is responsible for the largest proportion of total glutamate transport. Recently, it has been demonstrated that ceftriaxone (CEF) robustly increases GLT-1 expression. In addition, physiological studies have shown that GLT-1 up-regulation strongly affects synaptic plasticity, and leads to an impairment of the prepulse inhibition, a simple form of information processing, thus suggesting that GLT-1 over-expression may lead to dysfunctions of large populations of neurons. To test this possibility, we assessed whether CEF affects cortical electrical activity by using chronic electroencephalographic (EEG) recordings in male WKY rats. Spectral analysis showed that 8 days of CEF treatment resulted in a delayed reduction in EEG theta power (7–9 Hz) in both frontal and parietal derivations. This decrease peaked at day 10, i.e., 2 days after the end of treatment, and disappeared by day 16. In addition, we found that the same CEF treatment increased motor activity, especially when EEG changes are more prominent. Taken together, these data indicate that GLT-1 up-regulation, by modulating glutamatergic transmission, impairs the activity of widespread neural circuits. In addition, the increased motor activity and prepulse inhibition alterations previously described suggest that neural circuits involved in sensorimotor control are particularly sensitive to GLT-1 up-regulation. PMID:22479544

Reduction of EEG theta power and changes in motor activity in rats treated with ceftriaxone.

PubMed

Bellesi, Michele; Vyazovskiy, Vladyslav V; Tononi, Giulio; Cirelli, Chiara; Conti, Fiorenzo

2012-01-01

The glutamate transporter GLT-1 is responsible for the largest proportion of total glutamate transport. Recently, it has been demonstrated that ceftriaxone (CEF) robustly increases GLT-1 expression. In addition, physiological studies have shown that GLT-1 up-regulation strongly affects synaptic plasticity, and leads to an impairment of the prepulse inhibition, a simple form of information processing, thus suggesting that GLT-1 over-expression may lead to dysfunctions of large populations of neurons. To test this possibility, we assessed whether CEF affects cortical electrical activity by using chronic electroencephalographic (EEG) recordings in male WKY rats. Spectral analysis showed that 8 days of CEF treatment resulted in a delayed reduction in EEG theta power (7-9 Hz) in both frontal and parietal derivations. This decrease peaked at day 10, i.e., 2 days after the end of treatment, and disappeared by day 16. In addition, we found that the same CEF treatment increased motor activity, especially when EEG changes are more prominent. Taken together, these data indicate that GLT-1 up-regulation, by modulating glutamatergic transmission, impairs the activity of widespread neural circuits. In addition, the increased motor activity and prepulse inhibition alterations previously described suggest that neural circuits involved in sensorimotor control are particularly sensitive to GLT-1 up-regulation.

Relations between Playing Activities and Fine Motor Development

ERIC Educational Resources Information Center

Suggate, Sebastian; Stoeger, Heidrun; Pufke, Eva

2017-01-01

Children's fine motor skills (FMS) are being increasingly recognized as an important aspect of preschool development; yet, we know very little about the experiences that foster their development. We utilized a parent-administered children's fine and gross motor activities questionnaire (MAQ) to investigate links with FMS. We recruited a sample of…

Learning-induced Dependence of Neuronal Activity in Primary Motor Cortex on Motor Task Condition.

PubMed

Cai, X; Shimansky, Y; He, Jiping

2005-01-01

A brain-computer interface (BCI) system such as a cortically controlled robotic arm must have a capacity of adjusting its function to a specific environmental condition. We studied this capacity in non-human primates based on chronic multi-electrode recording from the primary motor cortex of a monkey during the animal's performance of a center-out 3D reaching task and adaptation to external force perturbations. The main condition-related feature of motor cortical activity observed before the onset of force perturbation was a phasic raise of activity immediately before the perturbation onset. This feature was observed during a series of perturbation trials, but were absent under no perturbations. After adaptation has been completed, it usually was taking the subject only one trial to recognize a change in the condition to switch the neuronal activity accordingly. These condition-dependent features of neuronal activity can be used by a BCI for recognizing a change in the environmental condition and making corresponding adjustments, which requires that the BCI-based control system possess such advanced properties of the neural motor control system as capacity to learn and adapt.

Risk factors affecting visual-motor coordination deficit among children residing near a petrochemical industrial estate.

PubMed

Aungudornpukdee, P; Vichit-Vadakan, N

2009-12-01

Thailand has been changed to rapid urbanization and industrialization since 1980s. During 1992 through 1996, the number of industrial factories in Rayong province increased very sharply. The major types of industries are petrol-chemical and plastic production. However, after the petrochemical industry boomed, the higher demand led to an industrial area expansion. The establishment of factories in this area leads to serious environmental and health impacts. The study aims to investigate the factors that affect visual-motor coordination deficit among children, 6-13 years of age, residing near the Petrochemical Industrial Estate, Map Ta Phut, Rayong province. A population-based cross-sectional study was employed for collecting data on neurobehavioral effects using the Digit Symbol Test. The study found one-third of 2,956 children presented with visual-motor coordination deficits. Three factors were identified that caused children to have a higher risk of visual-motor coordination deficits: gender (adjusted OR 1.934), monthly parental income (range of adjusted OR 1.977 - 2.612), and household environmental tobacco smoke (adjusted OR 1.284), while age (adjusted OR 0.874) and living period (adjusted OR 0.954) in study areas were reversed effects on visual-motor coordination deficit among children. The finding indicated that children with visual-motor coordination deficit were affected by gender, monthly parental income, age of children, length of living period, and household environmental tobacco smoke.

Sodium Pumps Mediate Activity-Dependent Changes in Mammalian Motor Networks

PubMed Central

Picton, Laurence D.; Nascimento, Filipe; Broadhead, Matthew J.; Sillar, Keith T.

2017-01-01

Ubiquitously expressed sodium pumps are best known for maintaining the ionic gradients and resting membrane potential required for generating action potentials. However, activity- and state-dependent changes in pump activity can also influence neuronal firing and regulate rhythmic network output. Here we demonstrate that changes in sodium pump activity regulate locomotor networks in the spinal cord of neonatal mice. The sodium pump inhibitor, ouabain, increased the frequency and decreased the amplitude of drug-induced locomotor bursting, effects that were dependent on the presence of the neuromodulator dopamine. Conversely, activating the pump with the sodium ionophore monensin decreased burst frequency. When more “natural” locomotor output was evoked using dorsal-root stimulation, ouabain increased burst frequency and extended locomotor episode duration, whereas monensin slowed and shortened episodes. Decreasing the time between dorsal-root stimulation, and therefore interepisode interval, also shortened and slowed activity, suggesting that pump activity encodes information about past network output and contributes to feedforward control of subsequent locomotor bouts. Using whole-cell patch-clamp recordings from spinal motoneurons and interneurons, we describe a long-duration (∼60 s), activity-dependent, TTX- and ouabain-sensitive, hyperpolarization (∼5 mV), which is mediated by spike-dependent increases in pump activity. The duration of this dynamic pump potential is enhanced by dopamine. Our results therefore reveal sodium pumps as dynamic regulators of mammalian spinal motor networks that can also be affected by neuromodulatory systems. Given the involvement of sodium pumps in movement disorders, such as amyotrophic lateral sclerosis and rapid-onset dystonia parkinsonism, knowledge of their contribution to motor network regulation also has considerable clinical importance. SIGNIFICANCE STATEMENT The sodium pump is ubiquitously expressed and responsible

Functional Semi-Blind Source Separation Identifies Primary Motor Area Without Active Motor Execution.

PubMed

Porcaro, Camillo; Cottone, Carlo; Cancelli, Andrea; Salustri, Carlo; Tecchio, Franca

2018-04-01

High time resolution techniques are crucial for investigating the brain in action. Here, we propose a method to identify a section of the upper-limb motor area representation (FS_M1) by means of electroencephalographic (EEG) signals recorded during a completely passive condition (FS_M1bySS). We delivered a galvanic stimulation to the median nerve and we applied to EEG the semi-Blind Source Separation (s-BSS) algorithm named Functional Source Separation (FSS). In order to prove that FS_M1bySS is part of FS_M1, we also collected EEG in a motor condition, i.e. during a voluntary movement task (isometric handgrip) and in a rest condition, i.e. at rest with eyes open and closed. In motor condition, we show that the cortico-muscular coherence (CMC) of FS_M1bySS does not differ from FS_ M1 CMC (0.04 for both sources). Moreover, we show that the FS_M1bySS's ongoing whole band activity during Motor and both rest conditions displays high mutual information and time correlation with FS_M1 (above 0.900 and 0.800, respectively) whereas much smaller ones with the primary somatosensory cortex [Formula: see text] (about 0.300 and 0.500, [Formula: see text]). FS_M1bySS as a marker of the upper-limb FS_M1 representation obtainable without the execution of an active motor task is a great achievement of the FSS algorithm, relevant in most experimental, neurological and psychiatric protocols.

Coin Tossing Explains the Activity of Opposing Microtubule Motors on Phagosomes.

PubMed

Sanghavi, Paulomi; D'Souza, Ashwin; Rai, Ashim; Rai, Arpan; Padinhatheeri, Ranjith; Mallik, Roop

2018-05-07

How the opposing activity of kinesin and dynein motors generates polarized distribution of organelles inside cells is poorly understood and hotly debated [1, 2]. Possible explanations include stochastic mechanical competition [3, 4], coordinated regulation by motor-associated proteins [5-7], mechanical activation of motors [8], and lipid-induced organization [9]. Here, we address this question by using phagocytosed latex beads to generate early phagosomes (EPs) that move bidirectionally along microtubules (MTs) in an in vitro assay [9]. Dynein/kinesin activity on individual EPs is recorded as real-time force generation of the motors against an optical trap. Activity of one class of motors frequently coincides with, or is rapidly followed by opposite motors. This leads to frequent and rapid reversals of EPs in the trap. Remarkably, the choice between dynein and kinesin can be explained by the tossing of a coin. Opposing motors therefore appear to function stochastically and independently of each other, as also confirmed by observing no effect on kinesin function when dynein is inhibited on the EPs. A simple binomial probability calculation based on the geometry of EP-microtubule contact explains the observed activity of dynein and kinesin on phagosomes. This understanding of intracellular transport in terms of a hypothetical coin, if it holds true for other cargoes, provides a conceptual framework to explain the polarized localization of organelles inside cells. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Effect of viscous fiber (guar) on postprandial motor activity in human small bowel.

PubMed

Schönfeld, J; Evans, D F; Wingate, D L

1997-08-01

Both caloric value and chemical composition of a meal have been shown to regulate postprandial small bowel motility in dog. In the same species, duration of and contractile activity within the postprandial period also depends on mean viscosity. It is unknown, however, whether meal viscosity and fiber content also regulate small bowel motor activity in man. In human volunteers, we therefore studied the effect of guar gum on small bowel motor response to liquid and solid meals. Twenty-six prolonged ambulatory small bowel manometry studies were performed in 12 volunteers. A total of 620 hr of recording were analyzed visually for phase III of the MMC and a validated computer program calculated the incidence and amplitude of contractions after ingestion of water (300 ml), a pure glucose drink (300 ml/330 kcal) or a solid meal (530 kcal) with and without 5 g of guar gum. Addition of 5 g of guar gum did not significantly delay reappearance of phase III after ingestion of water (59 +/- 11 vs 106 +/- 21 min; P = 0.09). However, guar gum significantly prolonged duration of postprandial motility pattern both after the glucose drink (123 +/- 19 vs 199 +/- 24 min; P < 0.05) and after the solid meal (310 +/- 92 vs 419 +/- 22 min; P = 0.005). Contractile activity during these periods was not affected by guar gum. This was true for mean incidence of contractions after water (1.9 +/- 0.3 vs 1.8 +/- 0.5 min-1), after the glucose drink (1.6 +/- 0.4 vs. 1.7 +/- 0.3 min-1) and after the solid meal (2.4 +/- 0.4 vs 2.6 +/- 0.4 min-1). Likewise, mean amplitude of contractions was not affected by guar gum after water (22.8 +/- 1.4 vs 20.9 +/- 1.9 mm Hg), after the glucose drink (20.5 +/- 1.4 vs 21.3 +/- 1.2), and after the solid meal (20.3 +/- 1.5 vs 21.5 +/- 1.6 mm Hg). Thus a guar gum-induced increase in chyme viscosity markedly prolonged duration of postprandial motor activity in the human small bowel. Contractile activity within the postprandial period, however, was not affected. We

Perception and motor activity: reality is always virtual

NASA Astrophysics Data System (ADS)

Bridgeman, Bruce

1999-05-01

We differentiate a cognitive branch of the visual system from a sensorimotor branch with the Roelofs, effect, a perception that a target's position is biased in the direction opposite the offset of a surrounding frame. Previous research left the possibility that accurate motor responses to a perceptually mislocated target might be mediated by oculomotor fixation of the target. Subjects performed judging and jabbing tasks to probe cognitive and motor system representations respectively while engaging in a saccadic task that prevented fixation of the target. Three experiments with an oculomotor distractor task evaluated judging and jabbing responses to the target. Three experiments did not show a Roelofs effect in spite of the prevention of fixation on the target. Motor response did not show a Roelofs effect in spite of the prevention of fixation on the target. Further, a decision about which of two targets to jab does not result in cognitive-system information affect motor response. The Roelofs effect was presented, however, in judging trials that also involved the saccadic task.

A Circuit for Motor Cortical Modulation of Auditory Cortical Activity

PubMed Central

Nelson, Anders; Schneider, David M.; Takatoh, Jun; Sakurai, Katsuyasu; Wang, Fan

2013-01-01

Normal hearing depends on the ability to distinguish self-generated sounds from other sounds, and this ability is thought to involve neural circuits that convey copies of motor command signals to various levels of the auditory system. Although such interactions at the cortical level are believed to facilitate auditory comprehension during movements and drive auditory hallucinations in pathological states, the synaptic organization and function of circuitry linking the motor and auditory cortices remain unclear. Here we describe experiments in the mouse that characterize circuitry well suited to transmit motor-related signals to the auditory cortex. Using retrograde viral tracing, we established that neurons in superficial and deep layers of the medial agranular motor cortex (M2) project directly to the auditory cortex and that the axons of some of these deep-layer cells also target brainstem motor regions. Using in vitro whole-cell physiology, optogenetics, and pharmacology, we determined that M2 axons make excitatory synapses in the auditory cortex but exert a primarily suppressive effect on auditory cortical neuron activity mediated in part by feedforward inhibition involving parvalbumin-positive interneurons. Using in vivo intracellular physiology, optogenetics, and sound playback, we also found that directly activating M2 axon terminals in the auditory cortex suppresses spontaneous and stimulus-evoked synaptic activity in auditory cortical neurons and that this effect depends on the relative timing of motor cortical activity and auditory stimulation. These experiments delineate the structural and functional properties of a corticocortical circuit that could enable movement-related suppression of auditory cortical activity. PMID:24005287

[Motor activity in psychogenic arm palsy confirmed by polysomnography (clinical case)].

PubMed

Diukova, G M; Poluektov, M G; Golubev, V L; Efetova, L E; Tsenteradze, S L

2017-01-01

According to current criteria, the diagnosis of psychogenic motor defect is based on the tests which allow recording of movements in the pseudo-paralyzed extremity. Using polysomnography, electromyography and videomonitoring of motor activities during sleep, movements in the pseudo-paralyzed left arm were recorded in a patient with Munchhausen syndrome and psychogenic plegia in the left arm. A reduced motor activity in the left side of the body, in particular in the pseudo-paralyzed arm was observed as well. Possibilities of using movement monitoring during sleep for the diagnosis of psychogenic motor defect are discussed.

Cytoskeletal motor-driven active self-assembly in in vitro systems

DOE PAGES

Lam, A. T.; VanDelinder, V.; Kabir, A. M. R.; ...

2015-11-11

Molecular motor-driven self-assembly has been an active area of soft matter research for the past decade. Because molecular motors transform chemical energy into mechanical work, systems which employ molecular motors to drive self-assembly processes are able to overcome kinetic and thermodynamic limits on assembly time, size, complexity, and structure. Here, we review the progress in elucidating and demonstrating the rules and capabilities of motor-driven active self-assembly. Lastly, we focus on the types of structures created and the degree of control realized over these structures, and discuss the next steps necessary to achieve the full potential of this assembly mode whichmore » complements robotic manipulation and passive self-assembly.« less

Association between late-life social activity and motor decline in older adults.

PubMed

Buchman, Aron S; Boyle, Patricia A; Wilson, Robert S; Fleischman, Debra A; Leurgans, Sue; Bennett, David A

2009-06-22

Loss of motor function is a common consequence of aging, but little is known about the factors that predict idiopathic motor decline. Our objective was to test the hypothesis that late-life social activity is related to the rate of change in motor function in old age. Longitudinal cohort study with a mean follow-up of 4.9 years with 906 persons without stroke, Parkinson disease, or dementia participating in the Rush Memory and Aging Project. At baseline, participants rated the frequency of their current participation in common social activities from which a summary measure of social activity was derived. The main outcome measure was annual change in a composite measure of global motor function, based on 9 measures of muscle strength and 9 motor performances. Mean (SD) social activity score at baseline was 2.6 (0.58), with higher scores indicating more frequent participation in social activities. In a generalized estimating equation model, controlling for age, sex, and education, global motor function declined by approximately 0.05 U/y (estimate, 0.016; 95% confidence interval [CI], -0.057 to 0.041 [P = .02]). Each 1-point decrease in social activity was associated with approximately a 33% more rapid rate of decline in motor function (estimate, 0.016; 95% CI, 0.003 to 0.029 [P = .02]). The effect of each 1-point decrease in the social activity score at baseline on the rate of change in global motor function was the same as being approximately 5 years older at baseline (age estimate, -0.003; 95% CI, -0.004 to -0.002 [P<.001]). Furthermore, this amount of motor decline per year was associated with a more than 40% increased risk of death (hazard ratio, 1.44; 95% CI, 1.30 to 1.60) and a 65% increased risk of incident Katz disability (hazard ratio, 1.65; 95% CI, 1.48 to 1.83). The association of social activity with the rate of global motor decline did not vary along demographic lines and was unchanged (estimate, 0.025; 95% CI, 0.005 to 0.045 [P = .01]) after controlling

Previous motor activity affects the transition from uncertainty to decision making in snails.

PubMed

Korshunova, Tatiana A; Vorontsov, Dmitry D; Dyakonova, Varvara E

2016-11-15

One of the most widely accepted benefits of enhanced physical activity is an improvement in the symptoms of depression, including the facilitation of decision making. Up until now, these effects have been shown in rodents and humans only. Little is known about their evolutionary origin or biological basis, and the underlying cellular mechanisms also remain relatively elusive. Here, we demonstrate for the first time that preceding motor activity accelerates decision making in an invertebrate, the pond snail Lymnaea stagnalis To investigate decision making in a novel environment, snails, which normally live in water, were placed on a flat dry surface to simulate the potentially threatening consequence of being in an arid environment. This stimulus initiated two distinct phases in snail behaviour: slow circular movements, followed by intense locomotion in a chosen direction. The first phase was prolonged when the test arena was symmetrically lit, compared with one with an apparent gradient of light. However, forced muscular locomotion for 2 h prior to the test promoted the transition from random circular motions to a directional crawl, accompanied by an increase in crawling speed but with no effect on the choice of direction. Intense locomotion for 2 h also produced a strong excitatory effect on the activity of serotonergic neurons in L. stagnalis Our results suggest that the beneficial effects of physical exercise on cognitive performance in mammals might have deep roots in evolution, granting the opportunity to unravel the origins of such effects at the single-neuron and network levels. © 2016. Published by The Company of Biologists Ltd.

Association between Late-Life Social Activity and Motor Decline in Older Adults

PubMed Central

Buchman, Aron S.; Boyle, Patricia A.; Wilson, Robert S.; Fleischman, Debra A.; Leurgans, Sue; Bennett, David A.

2009-01-01

Background Loss of motor function is a common consequence of aging, but little is known about factors that predict idiopathic motor decline. Methods We studied 906 persons without dementia, history of stroke or Parkinson's disease participating in the Rush Memory and Aging Project. At baseline, they rated their frequency of participation in common social activities. Outcome was annual change in global motor function, based on nine measures of muscle strength and nine motor performances. Results Mean social activity score at baseline was 2.6 (SD=0.58), with higher scores indicating more frequent participation in social activities. In a generalized estimating equation model, controlling for age, sex and education, motor function declined by about 0.05 unit/year [Estimate, 0.016; 95%CI (-0.057, -0.041); p=0.017]. Each 1-point decrease in social activity was associated with about a 33% more rapid rate of decline in motor function [Estimate, 0.016; 95%CI (0.003, 0.029); p=0.017)]. This amount of annual motor decline was associated with a more than 40% increased risk of death (Hazard Ratio: 1.44; 95%CI: 1.30, 1.60) and 65% increased risk of incident Katz disability (Hazard Ratio: 1.65; 95%CI: 1.48, 1.83). The association of social activity with change in motor function did not vary along demographic lines and was unchanged after controlling for potential confounders including late-life physical and cognitive activity, disability, global cognition, depressive symptoms, body composition and chronic medical conditions [Estimate, 0.025; 95%CI (0.005, 0.045); p=0.010]. Conclusion Less frequent participation in social activities is associated with a more rapid rate of motor decline in old age. PMID:19546415

The relationship between actual motor competence and physical activity in children: mediating roles of perceived motor competence and health-related physical fitness.

PubMed

Khodaverdi, Zeinab; Bahram, Abbas; Stodden, David; Kazemnejad, Anoshirvan

2016-08-01

The purpose of this study was to investigate whether perceived motor competence and components of health-related physical fitness mediated the relationship between actual motor competence and physical activity in 8- to 9-year-old Iranian girls. A convenience sample of 352 girls (mean age = 8.7, SD = 0.3 years) participated in the study. Actual motor competence, perceived motor competence and children's physical activity were assessed using the Test of Gross Motor Development-2, the physical ability sub-scale of Marsh's Self-Description Questionnaire and Physical Activity Questionnaire for Older Children, respectively. Body mass index, the 600 yard run/walk, curl-ups, push-ups, and back-saver sit and reach tests assessed health-related physical fitness. Preacher & Hayes (2004) bootstrap method was used to assess the potential mediating effects of fitness and perceived competence on the direct relationship between actual motor competence and physical activity. Regression analyses revealed that aerobic fitness (b = .28, 95% CI = [.21, .39]), as the only fitness measure, and perceived competence (b = .16, 95% CI = [.12, .32]) were measures that mediated the relationship between actual motor competence and physical activity with the models. Development of strategies targeting motor skill acquisition, children's self-perceptions of competence and cardiorespiratory fitness should be targeted to promote girls' moderate-to-vigorous physical activity.

Learning new gait patterns: Exploratory muscle activity during motor learning is not predicted by motor modules

PubMed Central

Ranganathan, Rajiv; Krishnan, Chandramouli; Dhaher, Yasin Y.; Rymer, William Z.

2018-01-01

The motor module hypothesis in motor control proposes that the nervous system can simplify the problem of controlling a large number of muscles in human movement by grouping muscles into a smaller number of modules. Here, we tested one prediction of the modular organization hypothesis by examining whether there is preferential exploration along these motor modules during the learning of a new gait pattern. Healthy college-aged participants learned a new gait pattern which required increased hip and knee flexion during the swing phase while walking in a lower-extremity robot (Lokomat). The new gait pattern was displayed as a foot trajectory in the sagittal plane and participants attempted to match their foot trajectory to this template. We recorded EMG from 8 lower-extremity muscles and we extracted motor modules during both baseline walking and target-tracking using non-negative matrix factorization (NMF). Results showed increased trajectory variability in the first block of learning, indicating that participants were engaged in exploratory behavior. Critically, when we examined the muscle activity during this exploratory phase, we found that the composition of motor modules changed significantly within the first few strides of attempting the new gait pattern. The lack of persistence of the motor modules under even short time scales suggests that motor modules extracted during locomotion may be more indicative of correlated muscle activity induced by the task constraints of walking, rather than reflecting a modular control strategy. PMID:26916510

Contribution from motor unit firing adaptations and muscle co-activation during fatigue.

PubMed

Contessa, Paola; Letizi, John; De Luca, Gianluca; Kline, Joshua C

2018-03-14

The control of motor unit firing behavior during fatigue is still debated in the literature. Most studies agree that the central nervous system increases the excitation to the motoneuron pool to compensate for decreased force contributions of individual motor units and sustain muscle force output during fatigue. However, some studies claim that motor units may decrease their firing rates despite increased excitation, contradicting the direct relationship between firing rates and excitation that governs the voluntary control of motor units. To investigate whether the control of motor units in fact changes with fatigue, we measured motor unit firing behavior during repeated contractions of the first dorsal interosseous (FDI) muscle while concurrently monitoring the activation of surrounding muscles - including the flexor carpi radialis, extensor carpi radialis, and pronator teres. Across all subjects, we observed an overall increase in FDI activation and motor unit firing rates by the end of the fatigue task. However, in some subjects we observed increases in FDI activation and motor unit firing rates only during the initial phase of the fatigue task, followed by subsequent decreases during the late phase of the fatigue task while the co-activation of surrounding muscles increased. These findings indicate that the strategy for sustaining force output may occasionally change leading to increases in the relative activation of surrounding muscles while the excitation to the fatiguing muscle decreases. Importantly, irrespective of changes in the strategy for sustaining force output, the control properties regulating motor unit firing behavior remain unchanged during fatigue.

Associations among Elementary School Children’s Actual Motor Competence, Perceived Motor Competence, Physical Activity and BMI: A Cross-Sectional Study

PubMed Central

Stodden, David; Brian, Ali; True, Larissa; Cardon, Greet; Tallir, Isabel; Haerens, Leen

2016-01-01

Background Positive associations between motor competence and physical activity have been identified by means of variable-centered analyses. To expand the understanding of these associations, this study used a person-centered approach to investigate whether different combinations (i.e., profiles) of actual and perceived motor competence exist (aim 1); and to examine differences in physical activity levels (aim 2) and weight status (aim 3) among children with different motor competence-based profiles. Materials and Methods Children’s (N = 361; 180 boys = 50%; Mage = 9.50±1.24yrs) actual motor competence was measured with the Test of Gross Motor Development-2 and their perceived motor competence via the Self Perception Profile for Children. We assessed physical activity via accelerometers; height through stadiometers, and weight through scales. Cluster analyses (aim 1) and MANCOVAs (aim 2 & 3) were used to analyze the data. Results The analysis generated two predictable groups: one group displaying relatively high levels of both actual (M TGMD-2 percentile = 42.54, SD = 2.33) and perceived motor competence (M = 3.42, SD = .37; high-high), and one group with relatively low levels of both (M percentile = 9.71, SD = 3.21; M PMC = 2.52, SD = .35; low-low). One additional group was also identified as having relatively low levels of actual motor competence (M percentile = 4.22, SD = 2.85) but relatively high levels of perceived motor competence (M = 3.52, SD = .30; low-high). The high-high group demonstrated higher daily physical activity (M = 48.39±2.03) and lower BMI (M = 18.13±.43) than the low-low group (MMVPA = 37.93±2.01; MBMI = 20.22±.42). The low-high group had similar physical activity-levels as the low-low group (M = 36.21±2.18) and did not significantly differ in BMI (M = 19.49±.46) from the other two groups. Conclusions A combination of high actual and perceived motor competence is related to higher physical activity and lower weight status. It is thus

Coordination of Fictive Motor Activity in the Larval Zebrafish Is Generated by Non-Segmental Mechanisms

PubMed Central

Wiggin, Timothy D.; Peck, Jack H.; Masino, Mark A.

2014-01-01

The cellular and network basis for most vertebrate locomotor central pattern generators (CPGs) is incompletely characterized, but organizational models based on known CPG architectures have been proposed. Segmental models propose that each spinal segment contains a circuit that controls local coordination and sends longer projections to coordinate activity between segments. Unsegmented/continuous models propose that patterned motor output is driven by gradients of neurons and synapses that do not have segmental boundaries. We tested these ideas in the larval zebrafish, an animal that swims in discrete episodes, each of which is composed of coordinated motor bursts that progress rostrocaudally and alternate from side to side. We perturbed the spinal cord using spinal transections or strychnine application and measured the effect on fictive motor output. Spinal transections eliminated episode structure, and reduced both rostrocaudal and side-to-side coordination. Preparations with fewer intact segments were more severely affected, and preparations consisting of midbody and caudal segments were more severely affected than those consisting of rostral segments. In reduced preparations with the same number of intact spinal segments, side-to-side coordination was more severely disrupted than rostrocaudal coordination. Reducing glycine receptor signaling with strychnine reversibly disrupted both rostrocaudal and side-to-side coordination in spinalized larvae without disrupting episodic structure. Both spinal transection and strychnine decreased the stability of the motor rhythm, but this effect was not causal in reducing coordination. These results are inconsistent with a segmented model of the spinal cord and are better explained by a continuous model in which motor neuron coordination is controlled by segment-spanning microcircuits. PMID:25275377

Comparison of psychopathological dimensions between major depressive disorder and schizophrenia spectrum disorders focusing on language, affectivity and motor behavior.

PubMed

Steinau, Sarah; Stegmayer, Katharina; Lang, Fabian U; Jäger, Markus; Strik, Werner; Walther, Sebastian

2017-04-01

This study tested whether patients with major depressive disorder (MDD) and schizophrenia spectrum disorders would differ in three dimensions of psychopathology (language, affectivity and motor behavior) as assessed by the Bern Psychopathology Scale (BPS) in a cohort of 58 patients with MDD and 146 patients with schizophrenia spectrum disorders. The overall estimation of severity of each of the three dimensions was rated on a seven-point Likert scale from severely inhibited to severely disinhibited. Here, more than half of the patients endorsed ratings that showed normal or mildly (dis-)inhibited behavior. At group level more pronounced negative ratings of affect were seen in MDD. Group comparisons of the severity ratings on language or motor behavior yielded no differences between schizophrenia spectrum disorders and MDD. At the individuals' levels, extreme ratings in the language and motor dimensions were more frequent in schizophrenia spectrum disorders and in the affectivity dimension more frequent in MDD. Shared psychopathological features could be seen across diagnoses, supporting a dimensional approach to psychopathology in endogenous psychoses. However, the groups differ in the severity of affect ratings as well as in the distribution of language, affectivity and motor ratings with more variance among the group of schizophrenia spectrum disorders. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Aberrant Neuromagnetic Activation in the Motor Cortex in Children with Acute Migraine: A Magnetoencephalography Study

PubMed Central

Guo, Xinyao; Xiang, Jing; Wang, Yingying; O’Brien, Hope; Kabbouche, Marielle; Horn, Paul; Powers, Scott W.; Hershey, Andrew D.

2012-01-01

Migraine attacks have been shown to interfere with normal function in the brain such as motor or sensory function. However, to date, there has been no clinical neurophysiology study focusing on the motor function in children with migraine during headache attacks. To investigate the motor function in children with migraine, twenty-six children with acute migraine, meeting International Classification of Headache Disorders criteria and age- and gender-matched healthy children were studied using a 275-channel magnetoencephalography system. A finger-tapping paradigm was designed to elicit neuromagnetic activation in the motor cortex. Children with migraine showed significantly prolonged latency of movement-evoked magnetic fields (MEF) during finger movement compared with the controls. The correlation coefficient of MEF latency and age in children with migraine was significantly different from that in healthy controls. The spectral power of high gamma (65–150 Hz) oscillations during finger movement in the primary motor cortex is also significantly higher in children with migraine than in controls. The alteration of responding latency and aberrant high gamma oscillations suggest that the developmental trajectory of motor function in children with migraine is impaired during migraine attacks and/or developmentally delayed. This finding indicates that childhood migraine may affect the development of brain function and result in long-term problems. PMID:23185541

Human primary motor cortex is both activated and stabilized during observation of other person's phasic motor actions.

PubMed

Hari, Riitta; Bourguignon, Mathieu; Piitulainen, Harri; Smeds, Eero; De Tiège, Xavier; Jousmäki, Veikko

2014-01-01

When your favourite athlete flops over the high-jump bar, you may twist your body in front of the TV screen. Such automatic motor facilitation, 'mirroring' or even overt imitation is not always appropriate. Here, we show, by monitoring motor-cortex brain rhythms with magnetoencephalography (MEG) in healthy adults, that viewing intermittent hand actions of another person, in addition to activation, phasically stabilizes the viewer's primary motor cortex, with the maximum of half a second after the onset of the seen movement. Such a stabilization was evident as enhanced cortex-muscle coherence at 16-20 Hz, despite signs of almost simultaneous suppression of rolandic rhythms of approximately 7 and 15 Hz as a sign of activation of the sensorimotor cortex. These findings suggest that inhibition suppresses motor output during viewing another person's actions, thereby withholding unintentional imitation.

Multimotor Transport in a System of Active and Inactive Kinesin-1 Motors

PubMed Central

Scharrel, Lara; Ma, Rui; Schneider, René; Jülicher, Frank; Diez, Stefan

2014-01-01

Long-range directional transport in cells is facilitated by microtubule-based motor proteins. One example is transport in a nerve cell, where small groups of motor proteins, such as kinesins and cytoplasmic dynein, work together to ensure the supply and clearance of cellular material along the axon. Defects in axonal transport have been linked to Alzheimer’s and other neurodegenerative diseases. However, it is not known in detail how multimotor-based cargo transport is impaired if a fraction of the motors are defective. To mimic impaired multimotor transport in vitro, we performed gliding motility assays with varying fractions of active kinesin-1 motors and inactive kinesin-1 motor mutants. We found that impaired transport manifests in multiple motility regimes: 1), a fast-motility regime characterized by gliding at velocities close to the single-molecule velocity of the active motors; 2), a slow-motility regime characterized by gliding at close-to zero velocity or full stopping; and 3), a regime in which fast and slow motilities coexist. Notably, the transition from the fast to the slow regime occurred sharply at a threshold fraction of active motors. Based on single-motor parameters, we developed a stochastic model and a mean-field theoretical description that explain our experimental findings. Our results demonstrate that impaired multimotor transport mostly occurs in an either/or fashion: depending on the ratio of active to inactive motors, transport is either performed at close to full speed or is out of action. PMID:25028878

The lifespan trajectory of neural oscillatory activity in the motor system.

PubMed

Heinrichs-Graham, Elizabeth; McDermott, Timothy J; Mills, Mackenzie S; Wiesman, Alex I; Wang, Yu-Ping; Stephen, Julia M; Calhoun, Vince D; Wilson, Tony W

2018-04-01

Numerous studies connect beta oscillations in the motor cortices to volitional movement, and beta is known to be aberrant in multiple movement disorders. However, the dynamic interplay between these beta oscillations, motor performance, and spontaneous beta power (e.g., during rest) in the motor cortices remains unknown. This study utilized magnetoencephalography (MEG) to investigate these three parameters and their lifespan trajectory in 57 healthy participants aged 9-75 years old. Movement-related beta activity was imaged using a beamforming approach, and voxel time series data were extracted from the peak voxels in the primary motor cortices. Our results indicated that spontaneous beta power during rest followed a quadratic lifespan trajectory, while movement-related beta oscillations linearly increased with age. Follow-on analyses showed that spontaneous beta power and the beta minima during movement, together, significantly predicted task performance above and beyond the effects of age. These data are the first to show lifespan trajectories among measures of beta activity in the motor cortices, and suggest that the healthy brain compensates for age-related increases in spontaneous beta activity by increasing the strength of beta oscillations within the motor cortices which, when successful, enables normal motor performance into later life. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Motor unit firing rates and synchronisation affect the fractal dimension of simulated surface electromyogram during isometric/isotonic contraction of vastus lateralis muscle.

PubMed

Mesin, Luca; Dardanello, Davide; Rainoldi, Alberto; Boccia, Gennaro

2016-12-01

During fatiguing contractions, many adjustments in motor units behaviour occur: decrease in muscle fibre conduction velocity; increase in motor units synchronisation; modulation of motor units firing rate; increase in variability of motor units inter-spike interval. We simulated the influence of all these adjustments on synthetic EMG signals in isometric/isotonic conditions. The fractal dimension of the EMG signal was found mainly influenced by motor units firing behaviour, being affected by both firing rate and synchronisation level, and least affected by muscle fibre conduction velocity. None of the calculated EMG indices was able to discriminate between firing rate and motor units synchronisation. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Probing intracellular motor protein activity using an inducible cargo trafficking assay.

PubMed

Kapitein, Lukas C; Schlager, Max A; van der Zwan, Wouter A; Wulf, Phebe S; Keijzer, Nanda; Hoogenraad, Casper C

2010-10-06

Although purified cytoskeletal motor proteins have been studied extensively with the use of in vitro approaches, a generic approach to selectively probe actin and microtubule-based motor protein activity inside living cells is lacking. To examine specific motor activity inside living cells, we utilized the FKBP-rapalog-FRB heterodimerization system to develop an in vivo peroxisomal trafficking assay that allows inducible recruitment of exogenous and endogenous kinesin, dynein, and myosin motors to drive specific cargo transport. We demonstrate that cargo rapidly redistributes with distinct dynamics for each respective motor, and that combined (antagonistic) actions of more complex motor combinations can also be probed. Of importance, robust cargo redistribution is readily achieved by one type of motor protein and does not require the presence of opposite-polarity motors. Simultaneous live-cell imaging of microtubules and kinesin or dynein-propelled peroxisomes, combined with high-resolution particle tracking, revealed that peroxisomes frequently pause at microtubule intersections. Titration and washout experiments furthermore revealed that motor recruitment by rapalog-induced heterodimerization is dose-dependent but irreversible. Our assay directly demonstrates that robust cargo motility does not require the presence of opposite-polarity motors, and can therefore be used to characterize the motile properties of specific types of motor proteins. Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

A positive association between active lifestyle and hemispheric lateralization for motor control and learning in older adults.

PubMed

Wang, Jinsung; D'Amato, Arthur; Bambrough, Jennifer; Swartz, Ann M; Miller, Nora E

2016-11-01

Physical activity (PA) is well known to have general health benefits for older adults, but it is unclear whether it can also positively affect brain function involved in motor control and learning. We have previously shown that interlimb transfer of visuomotor adaptation occurs asymmetrically in young adults, while that occurs symmetrically in older adults, which suggests that the lateralized function of each hemisphere during motor tasks is diminished with aging. Here, we investigated the association between the level of PA and hemispheric motor lateralization by comparing the pattern of interlimb transfer following visuomotor adaptation between physically active and inactive older adults. Subjects were divided into two groups based on their PA level (active, inactive). They were further divided into two groups, such that a half of the subjects in each group adapted to a 30° rotation during targeted reaching movements with the left arm first, then with the right arm; and the other half with the right arm first, then with the left arm. Results indicated asymmetrical transfer (from left to right only) in the active subjects, whereas symmetrical transfer (from left to right, and vice versa) was observed in the inactive subjects. These findings suggest that older adults who maintain active lifestyle have a central nervous system that is more intact in terms of its lateralized motor function as compared with those who are inactive. Copyright © 2016 Elsevier B.V. All rights reserved.

Analysis of automated quantification of motor activity in REM sleep behaviour disorder.

PubMed

Frandsen, Rune; Nikolic, Miki; Zoetmulder, Marielle; Kempfner, Lykke; Jennum, Poul

2015-10-01

Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by dream enactment and REM sleep without atonia. Atonia is evaluated on the basis of visual criteria, but there is a need for more objective, quantitative measurements. We aimed to define and optimize a method for establishing baseline and all other parameters in automatic quantifying submental motor activity during REM sleep. We analysed the electromyographic activity of the submental muscle in polysomnographs of 29 patients with idiopathic RBD (iRBD), 29 controls and 43 Parkinson's (PD) patients. Six adjustable parameters for motor activity were defined. Motor activity was detected and quantified automatically. The optimal parameters for separating RBD patients from controls were investigated by identifying the greatest area under the receiver operating curve from a total of 648 possible combinations. The optimal parameters were validated on PD patients. Automatic baseline estimation improved characterization of atonia during REM sleep, as it eliminates inter/intra-observer variability and can be standardized across diagnostic centres. We found an optimized method for quantifying motor activity during REM sleep. The method was stable and can be used to differentiate RBD from controls and to quantify motor activity during REM sleep in patients with neurodegeneration. No control had more than 30% of REM sleep with increased motor activity; patients with known RBD had as low activity as 4.5%. We developed and applied a sensitive, quantitative, automatic algorithm to evaluate loss of atonia in RBD patients. © 2015 European Sleep Research Society.

Music supported therapy promotes motor plasticity in individuals with chronic stroke.

PubMed

Ripollés, P; Rojo, N; Grau-Sánchez, J; Amengual, J L; Càmara, E; Marco-Pallarés, J; Juncadella, M; Vaquero, L; Rubio, F; Duarte, E; Garrido, C; Altenmüller, E; Münte, T F; Rodríguez-Fornells, A

2016-12-01

Novel rehabilitation interventions have improved motor recovery by induction of neural plasticity in individuals with stroke. Of these, Music-supported therapy (MST) is based on music training designed to restore motor deficits. Music training requires multimodal processing, involving the integration and co-operation of visual, motor, auditory, affective and cognitive systems. The main objective of this study was to assess, in a group of 20 individuals suffering from chronic stroke, the motor, cognitive, emotional and neuroplastic effects of MST. Using functional magnetic resonance imaging (fMRI) we observed a clear restitution of both activity and connectivity among auditory-motor regions of the affected hemisphere. Importantly, no differences were observed in this functional network in a healthy control group, ruling out possible confounds such as repeated imaging testing. Moreover, this increase in activity and connectivity between auditory and motor regions was accompanied by a functional improvement of the paretic hand. The present results confirm MST as a viable intervention to improve motor function in chronic stroke individuals.

Rhythmic motor activity and interlimb co-ordination in the developing pouch young of a wallaby (Macropus eugenii).

PubMed Central

Ho, S M

1997-01-01

1. The forelimb motor behaviour of developing wallaby was studied. A clock-like alternating movement was reactivated whenever the animal was removed from the pouch. 2. Forelimb stepping frequency increased during the first 3 weeks of development, while the phase relationship remained constant. Forelimb activity could be affected by altering the afferent feedback from the contralateral limb, or an increase in ambient temperature. 3. In vitro experiments were performed using an isolated brainstem-spinal cord preparation from animals up to 6 weeks postnatal. Fictive locomotor activity could be evoked by electrical stimulation or bath-applied NMDA (< 10 microM). 4. Bath-applied strychnine (10-25 microM) and bicuculline (10-50 microM) disrupted the phase relationship between motor pools, while rhythmic motor discharge remained in the absence of these inhibitory pathways. 5. The present findings indicate that the pattern generator that underlies the robust forelimb movement during the first journey to the pouch is retained for different motor functions during in-pouch development. The neural network that underlies such behaviour can be divided into two major components, a rhythm generator within each hemicord, and a pattern co-ordinating pathway which involve both glycinergic and GABAergic interneurones. PMID:9218221

Anticipatory activity in primary motor cortex codes memorized movement sequences.

PubMed

Lu, Xiaofeng; Ashe, James

2005-03-24

Movement sequences, defined both by the component movements and by the serial order in which they are produced, are fundamental building blocks of motor behavior. The serial order of sequence production is strongly encoded in medial motor areas. It is not known to what extent sequences are further elaborated or encoded in primary motor cortex. Here, we describe cells in the primary motor cortex of the monkey that show anticipatory activity exclusively related to a specific memorized sequence of upcoming movements. In addition, the injection of muscimol, a GABA agonist, into motor cortex resulted in an increase in the error rate during sequence production, without concomitant effects on nonsequenced motor performance. Our results challenge the role of medial motor areas in the control of well-practiced movement sequences and suggest that motor cortex contains a complete apparatus for the planning and production of this complex behavior.

Speech and motor disturbances in Rett syndrome.

PubMed

Bashina, V M; Simashkova, N V; Grachev, V V; Gorbachevskaya, N L

2002-01-01

Rett syndrome is a severe, genetically determined disease of early childhood which produces a defined clinical phenotype in girls. The main clinical manifestations include lesions affecting speech functions, involving both expressive and receptive speech, as well as motor functions, producing apraxia of the arms and profound abnormalities of gait in the form of ataxia-apraxia. Most investigators note that patients have variability in the severity of derangement to large motor acts and in the damage to fine hand movements and speech functions. The aims of the present work were to study disturbances of speech and motor functions over 2-5 years in 50 girls aged 12 months to 14 years with Rett syndrome and to analyze the correlations between these disturbances. The results of comparing clinical data and EEG traces supported the stepwise involvement of frontal and parietal-temporal cortical structures in the pathological process. The ability to organize speech and motor activity is affected first, with subsequent development of lesions to gnostic functions, which are in turn followed by derangement of subcortical structures and the cerebellum and later by damage to structures in the spinal cord. A clear correlation was found between the severity of lesions to motor and speech functions and neurophysiological data: the higher the level of preservation of elements of speech and motor functions, the smaller were the contributions of theta activity and the greater the contributions of alpha and beta activities to the EEG. The possible pathogenetic mechanisms underlying the motor and speech disturbances in Rett syndrome are discussed.

Effect of Early Physical Activity Programs on Motor Performance and Neuromuscular Development in Infants Born Preterm: A Randomized Clinical Trial

PubMed Central

Valizadeh, Leila; Sanaeefar, Mahnaz; Hosseini, Mohammad Bager; Asgari Jafarabadi, Mohammad; Shamili, Aryan

2017-01-01

Introduction: Although the survival rate of infants born preterm has increased, the prevalence of developmental problems and motor disorders among this population of infants remains the same. This study investigated the effect of physical activity programs in and out of water on motor performance and neuromuscular development of infants born preterm and had induced immobility by mechanical ventilation. Methods: This study was carried out in Al-Zahra hospital, Tabriz. 76 premature infants were randomly assigned into four groups. One group received daily passive range of motion to all extremities based on the Moyer-Mileur protocol. Hydrotherapy group received exercises for shoulders and pelvic area in water every other day. A combination group received physical activity programs in and out of water on alternating days. Infants in a containment group were held in a fetal position. Duration of study was two weeks ‘from 32 through 33 weeks post menstrual age (PMA). Motor outcomes were measured by the Test of Infant Motor Performance. Neuromuscular developmental was assessed by New Ballard scale and leg recoil and Ankle dorsiflexion items from Dubowitz scale. Data were analyzed using SPSS version 13. Results: TIMP and neuromuscular scores improved in all groups. Motor performance did not differ between groups at 34 weeks PMA. Postural tone of leg recoil was significantly higher in physical activity groups post intervention. Conclusion: Physical activities and containment didn’t have different effects on motor performance in infants born preterm. Leg recoil of neuromuscular development items was affected by physical activity programs. PMID:28299299

Motor Development and Physical Activity: A Longitudinal Discordant Twin-Pair Study.

PubMed

Aaltonen, Sari; Latvala, Antti; Rose, Richard J; Pulkkinen, Lea; Kujala, Urho M; Kaprio, Jaakko; Silventoinen, Karri

2015-10-01

Previous longitudinal research suggests that motor proficiency in early life predicts physical activity in adulthood. Familial effects including genetic and environmental factors could explain the association, but no long-term follow-up studies have taken into account potential confounding by genetic and social family background. The present twin study investigated whether childhood motor skill development is associated with leisure-time physical activity levels in adulthood independent of family background. Altogether, 1550 twin pairs from the FinnTwin12 study and 1752 twin pairs from the FinnTwin16 study were included in the analysis. Childhood motor development was assessed by the parents' report of whether one of the co-twins had been ahead of the other in different indicators of motor skill development in childhood. Leisure-time physical activity (MET·h·d) was self-reported by the twins in young adulthood and adulthood. Statistical analyses included conditional and ordinary linear regression models within twin pairs. Using all activity-discordant twin pairs, the within-pair difference in a sum score of motor development in childhood predicted the within-pair difference in the leisure-time physical activity level in young adulthood (P < 0.001). Within specific motor development indicators, learning to stand unaided earlier in infancy predicted higher leisure-time MET values in young adulthood statistically significantly in both samples (FinnTwin12, P = 0.02; and FinnTwin16, P = 0.001) and also in the pooled data set of the FinnTwin12 and FinnTwin16 studies (P < 0.001). Having been more agile than the co-twin as a child predicted higher leisure-time MET values up to adulthood (P = 0.03). More advanced childhood motor development is associated with higher leisure-time MET values in young adulthood at least partly independent of family background in both men and women.

MOTOR DEVELOPMENT AND PHYSICAL ACTIVITY: A LONGITUDINAL DISCORDANT TWIN-PAIR STUDY

PubMed Central

Aaltonen, Sari; Latvala, Antti; Rose, Richard J.; Pulkkinen, Lea; Kujala, Urho M.; Kaprio, Jaakko; Silventoinen, Karri

2015-01-01

Introduction Previous longitudinal research suggests that motor proficiency in early life predicts physical activity in adulthood. Familial effects including genetic and environmental factors could explain the association, but no long-term follow-up studies have taken into account potential confounding by genetic and social family background. The present twin study investigated whether childhood motor skill development is associated with leisure-time physical activity levels in adulthood independent of family background. Methods Altogether, 1 550 twin pairs from the FinnTwin12 study and 1 752 twin pairs from the FinnTwin16 study were included in the analysis. Childhood motor development was assessed by the parents’ report of whether one of the co-twins had been ahead of the other in different indicators of motor skill development in childhood. Leisure-time physical activity (MET hours/day) was self-reported by the twins in young adulthood and adulthood. Statistical analyses included conditional and ordinary linear regression models within twin pairs. Results Using all activity-discordant twin pairs, the within-pair difference in a sum score of motor development in childhood predicted the within-pair difference in the leisure-time physical activity level in young adulthood (p<0.001). Within specific motor development indicators, learning to stand unaided earlier in infancy predicted higher leisure-time MET values in young adulthood statistically significantly in both samples (FinnTwin12 p=0.02, FinnTwin16 p=0.001) and also in the pooled dataset of the FinnTwin12 and FinnTwin16 studies (p<0.001). Having been more agile than the co-twin as a child predicted higher leisure-time MET values up to adulthood (p=0.03). Conclusions More advanced childhood motor development is associated with higher leisure-time MET values in young adulthood at least partly independent of family background, in both men and women. PMID:26378945

On the Drive Specificity of Freudian Drives for the Generation of SEEKING Activities: The Importance of the Underestimated Imperative Motor Factor

PubMed Central

Kirsch, Michael; Mertens, Wolfgang

2018-01-01

Doubters of Freud’s theory of drives frequently mentioned that his approach is outdated and therefore cannot be useful for solving current problems in patients with mental disorders. At present, many scientists believe that affects rather than drives are of utmost importance for the emotional life and the theoretical framework of affective neuroscience, developed by Panksepp, strongly underpinned this view. Panksepp evaluated seven so-called command systems and the SEEKING system is therein of central importance. Panksepp used Pankseppian drives as inputs for the SEEKING system but noted the missing explanation of drive-specific generation of SEEKING activities in his description. Drive specificity requires dual action of the drive: the activation of a drive-specific brain area and the release of the neurotransmitter dopamine. Noticeably, as Freud claimed drive specificity too, it was here analyzed whether a Freudian drive can evoke the generation of drive-specific SEEKING activities. Special importance was addressed to the imperative motor factor in Freud’s drive theory because Panksepp’s formulations focused on neural pathways without specifying underlying neurotransmitter/endocrine factors impelling motor activity. As Panksepp claimed sleep as a Pankseppian drive, we firstly had to classified sleep as a Freudian drive by using three evaluated criteria for a Freudian drive. After that it was possible to identify the imperative motor factors of hunger, thirst, sex, and sleep. Most importantly, all of these imperative motor factors can both activate a drive-specific brain area and release dopamine from dopaminergic neurons, i.e., they can achieve the so-called drive specificity. Surprisingly, an impaired Freudian drive can alter via endocrinological pathways the concentration of the imperative motor factor of a second Freudian drive, obviously in some independence to the level of the metabolic deficit, thereby offering the possibility to modulate the

BicaudalD actively regulates microtubule motor activity in lipid droplet transport.

PubMed

Larsen, Kristoffer S; Xu, Jing; Cermelli, Silvia; Shu, Zhanyong; Gross, Steven P

2008-01-01

A great deal of sub-cellular organelle positioning, and essentially all minus-ended organelle transport, depends on cytoplasmic dynein, but how dynein's function is regulated is not well understood. BicD is established to play a critical role in mediating dynein function-loss of BicD results in improperly localized nuclei, mRNA particles, and a dispersed Golgi apparatus-however exactly what BicD's role is remains unknown. Nonetheless, it is widely believed that BicD may act to tether dynein to cargos. Here we use a combination of biophysical and biochemical studies to investigate BicD's role in lipid droplet transport during Drosophila embryogenesis. Functional loss of BicD impairs the embryo's ability to control the net direction of droplet transport; the developmentally controlled reversal in transport is eliminated. We find that minimal BicD expression (near-BicD(null)) decreases the average run length of both plus and minus end directed microtubule (MT) based transport. A point mutation affecting the BicD N-terminus has very similar effects on transport during cellularization (phase II), but in phase III (gastrulation) motion actually appears better than in the wild-type. In contrast to a simple static tethering model of BicD function, or a role only in initial dynein recruitment to the cargo, our data uncovers a new dynamic role for BicD in actively regulating transport. Lipid droplets move bi-directionally, and our investigations demonstrate that BicD plays a critical-and temporally changing-role in balancing the relative contributions of plus-end and minus-end motors to control the net direction of transport. Our results suggest that while BicD might contribute to recruitment of dynein to the cargo it is not absolutely required for such dynein localization, and it clearly contributes to regulation, helping activation/inactivation of the motors.

Educational Interventions for Visual-Motor Deficiencies That Affect Handwriting in School-Aged Children.

ERIC Educational Resources Information Center

Dikowski, Timothy J.

This practicum was designed to remediate handwriting skills in school-aged children who displayed visual-motor deficiencies that affect mechanical skills. Practicum goals were to: (1) identify and diagnose children with handwriting delays; (2) involve school and parent interaction by involving them with pre- and post-program assessment; (3)…

Periodic colonic motor activity identified by 24-h pancolonic ambulatory manometry in humans.

PubMed

Hagger, R; Kumar, Devinder; Benson, M; Grundy, A

2002-06-01

The pattern of colonic motor activity in healthy humans has not been fully elucidated to date. The aim of this study was to evaluate colorectal motor activity employing 24-h ambulant pancolonic manometry. Ten healthy volunteers (6F, 4M), aged 19-31 years were studied. Motor activity was measured using two custom-made silicone coated catheters, each with five solid-state pressure transducers. No bowel preparation or sedation was used. The study period was 24 h. A total of 232 h of recording was obtained. Sixty-three high amplitude propagated contractions were observed, median six per 24-h period. Low-amplitude colonic contractile activity showed regional and diurnal variations. Frequency of contraction was highest in the right colon [median 5.26 cpm (cycles per minute)], and transverse colon and splenic flexure (median 5.15 cpm). The interval between colonic motor complexes was shortest in the transverse colon and splenic flexure. This study introduces a new technique for the evaluation of colorectal motor activity. Subjects were studied in an ambulant setting in their own environment ensuring that this method of study is as physiological as possible. This study demonstrates that colonic motor activity has two main components: high amplitude propagated contractions and low amplitude colonic contractile activity.

Motor system contributions to verbal and non-verbal working memory.

PubMed

Liao, Diana A; Kronemer, Sharif I; Yau, Jeffrey M; Desmond, John E; Marvel, Cherie L

2014-01-01

Working memory (WM) involves the ability to maintain and manipulate information held in mind. Neuroimaging studies have shown that secondary motor areas activate during WM for verbal content (e.g., words or letters), in the absence of primary motor area activation. This activation pattern may reflect an inner speech mechanism supporting online phonological rehearsal. Here, we examined the causal relationship between motor system activity and WM processing by using transcranial magnetic stimulation (TMS) to manipulate motor system activity during WM rehearsal. We tested WM performance for verbalizable (words and pseudowords) and non-verbalizable (Chinese characters) visual information. We predicted that disruption of motor circuits would specifically affect WM processing of verbalizable information. We found that TMS targeting motor cortex slowed response times (RTs) on verbal WM trials with high (pseudoword) vs. low (real word) phonological load. However, non-verbal WM trials were also significantly slowed with motor TMS. WM performance was unaffected by sham stimulation or TMS over visual cortex (VC). Self-reported use of motor strategy predicted the degree of motor stimulation disruption on WM performance. These results provide evidence of the motor system's contributions to verbal and non-verbal WM processing. We speculate that the motor system supports WM by creating motor traces consistent with the type of information being rehearsed during maintenance.

Twitch analysis as an approach to motor unit activation during electrical stimulation.

PubMed

Heyters, M; Carpentier, A; Duchateau, J; Hainaut, K

1994-12-01

The mechanical twitch in response to increasing electrical stimulus intensity, delivered both over the motor point and motor nerve, was recorded in the first dorsal interosseous (FDI) and the adductor pollicis (AP), and only over the motor point in the soleus (Sol), lateral (LG), and medial (MG) gastrocnemius muscles of human subjects. The relationship between intensity of electrical stimulation (ES) and twitch torque showed a positive linear regression in all muscles. In the FDI and AP the relationship was not significantly different when ES was applied at the motor point or over the motor nerve. At small intensities of activation, ES induced larger twitch torques in the MG and LG, which contain a roughly equal proportion of slow and fast motor units (MUs) compared to the Sol, which is composed mainly of slow type fibres. Moreover, the relationship between ES intensity and twitch time-to-peak is best fitted in all muscles by a power curve that shows a greater twitch time-to-peak range in its initial part for muscles containing a larger proportion of fast MUs (LG, MG) than for muscles mainly composed of slow MUs (Sol). In conclusion, these results induced by ES at the motor point and/or over the motor nerve confirm the concept of a reversed sequence of MU activation, as compared to voluntary contractions, and document this viewpoint in muscles of different function and composition. The reversed sequence of MU activation is more clearly evident during motor point ES.

Actigraphically assessed activity in unipolar depression: a comparison of inpatients with and without motor retardation.

PubMed

Krane-Gartiser, Karoline; Henriksen, Tone E G; Vaaler, Arne E; Fasmer, Ole Bernt; Morken, Gunnar

2015-09-01

To compare the activity patterns of inpatients with unipolar depression, who had been divided into groups with and without motor retardation prior to actigraphy monitoring. Twenty-four-hour actigraphy recordings from 52 consecutively, acutely admitted inpatients with unipolar depression (ICD-10) were compared to recordings from 28 healthy controls. The patients, admitted between September 2011 and April 2012, were separated into 2 groups: 25 with motor retardation and 27 without motor retardation. Twenty-eight healthy controls were also included. Twenty-four-hour recordings, 9-hour daytime sequences, and 64-minute periods of continuous motor activity in the morning and evening were analyzed for mean activity, variability, and complexity. Patients with motor retardation had a reduced mean activity level (P = .04) and higher intraindividual variability, as shown by increased standard deviation (SD) (P = .003) and root mean square successive difference (RMSSD) (P = .025), during 24 hours compared to the patients without motor retardation. Both patient groups demonstrated significantly lower mean activity compared to healthy controls (P < .001) as well as higher SD (P < .02) and RMSSD (P < .001) and a higher RMSSD/SD ratio (P = .04). In the active morning period, the patients without motor retardation displayed significantly increased complexity compared to motor-retarded patients (P = .006). The patients with and without motor retardation differ in activity patterns. Findings in depressed inpatients without motor retardation closely resemble those of inpatients with mania. © Copyright 2015 Physicians Postgraduate Press, Inc.

Pacific Ciguatoxin Induces Excitotoxicity and Neurodegeneration in the Motor Cortex Via Caspase 3 Activation: Implication for Irreversible Motor Deficit.

PubMed

Asthana, Pallavi; Zhang, Ni; Kumar, Gajendra; Chine, Virendra Bhagawan; Singh, Kunal Kumar; Mak, Yim Ling; Chan, Leo Lai; Lam, Paul Kwan Sing; Ma, Chi Him Eddie

2018-01-18

Consumption of fish containing ciguatera toxins or ciguatoxins (CTXs) causes ciguatera fish poisoning (CFP). In some patients, CFP recurrence occurs even years after exposure related to CTXs accumulation. Pacific CTX-1 (P-CTX-1) is one of the most potent natural substances known that causes predominantly neurological symptoms in patients; however, the underlying pathogenies of CFP remain unknown. Using clinically relevant neurobehavioral tests and electromyography (EMG) to assess effects of P-CTX-1 during the 4 months after exposure, recurrent motor strength deficit occurred in mice exposed to P-CTX-1. We detected irreversible motor strength deficits accompanied by reduced EMG activity, demyelination, and slowing of motor nerve conduction, whereas control unexposed mice fully recovered in 1 month after peripheral nerve injury. Finally, to uncover the mechanism underlying CFP, we detected reduction of spontaneous firing rate of motor cortical neurons even 6 months after exposure and increased number of glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes. Increased numbers of motor cortical neuron apoptosis were detected by dUTP-digoxigenin nick end labeling assay along with activation of caspase 3. Taken together, our study demonstrates that persistence of P-CTX-1 in the nervous system induces irreversible motor deficit that correlates well with excitotoxicity and neurodegeneration detected in the motor cortical neurons.

Physiology of the motor cortex in polio survivors.

PubMed

Lupu, Vitalie D; Danielian, Laura; Johnsen, Jacqueline A; Vasconcelos, Olavo M; Prokhorenko, Olga A; Jabbari, Bahman; Campbell, William W; Floeter, Mary Kay

2008-02-01

We hypothesized that the corticospinal system undergoes functional changes in long-term polio survivors. Central motor conduction times (CMCTs) to the four limbs were measured in 24 polio survivors using transcranial magnetic stimulation (TMS). Resting motor thresholds and CMCTs were normal. In 17 subjects whose legs were affected by polio and 13 healthy controls, single- and paired-pulse TMS was used to assess motor cortex excitability while recording from tibialis anterior (TA) muscles at rest and following maximal contraction until fatigue. In polio survivors the slope of the recruitment curve was normal, but maximal motor evoked potentials (MEPs) were larger than in controls. MEPs were depressed after fatiguing exercise. Three patients with central fatigue by twitch interpolation had a trend toward slower recovery. There was no association with symptoms of post-polio syndrome. These changes occurring after polio may allow the motor cortex to activate a greater proportion of the motor neurons innervating affected muscles.

CORRELATION INDICES OF CEREBRAL HEMODYNAMICS AND ELECTRICAL ACTIVITY IN CHILDREN WITH IMPAIRED MOTOR SKILLS.

PubMed

Golovchenko, I V; Hayday, M I

The correlations between the indicators of cerebral hemodynamics and electrical activity in children with impaired motor skills of central origin (children with cerebral palsy) were investigated. There is established a high number of links between indicators of rheoencephalogram (REG) and electroencephalogram (EEG) in the left cerebral hemisphere than in the right. In frontomastoidal allocation 19 correlations and in occipitomastoidal - 59 links. We suppose that poor circulation in vertebroplasty-basilar system leads to the defeat of the brain stem, which, with afferent pathways of the reticular formation, connects the thalamus with the cortex. In the reticular formation there is an inhibition of ascending activators influences, which eland to decreasing of the cortex is tonus. You can talk about the functional immaturity of the system of nonspecific activation by the reticular formation of the brain stem. Children with violation of motor activity had significantly more negative and positive significant and high correlation among the existing indicators of electric brain activity and cerebral hemodynamics, in our opinion, is due to the development of interconnection compensation that is carried out by adjustment of the functional systems and the formation of new forms of adaptive responses in conditions of disontogenetik. Feature correlation pattern of the EEG, of children with disorders of motor activity, is associated with a significantly great number of high and significant correlations between measures of electrical brain activity in the δ- and q- rhythms, especially in the temporal areas of the cerebral cortex. According to visual analysis of EEG there is revealed a common manifestation of changes of bioelectric brain activity in children with disorders of motor activity. This is manifested in the development of paroxysmal activity of action potentials of θ- and δ-rhythms with the focus of activity in the anterior areas of the cerebral cortex; the formation

Transport dynamics of molecular motors that switch between an active and inactive state

NASA Astrophysics Data System (ADS)

Pinkoviezky, I.; Gov, N. S.

2013-08-01

Molecular motors are involved in key transport processes in the cell. Many of these motors can switch from an active to a nonactive state, either spontaneously or depending on their interaction with other molecules. When active, the motors move processively along the filaments, while when inactive they are stationary. We treat here the simple case of spontaneously switching motors, between the active and inactive states, along an open linear track. We use our recent analogy with vehicular traffic, where we go beyond the mean-field description. We map the phase diagram of this system, and find that it clearly breaks the symmetry between the different phases, as compared to the standard total asymmetric exclusion process. We make several predictions that may be testable using molecular motors in vitro and in living cells.

Exposure to GSM 900 MHz electromagnetic fields affects cerebral cytochrome c oxidase activity.

PubMed

Ammari, Mohamed; Lecomte, Anthony; Sakly, Mohsen; Abdelmelek, Hafedh; de-Seze, René

2008-08-19

The world-wide and rapidly growing use of mobile phones has raised serious concerns about the biological and health-related effects of radio frequency (RF) radiation, particularly concerns about the effects of RFs upon the nervous system. The goal of this study was conducted to measure cytochrome oxidase (CO) levels using histochemical methods in order to evaluate regional brain metabolic activity in rat brain after exposure to a GSM 900 MHz signal for 45 min/day at a brain-averaged specific absorption rate (SAR) of 1.5 W/Kg or for 15 min/day at a SAR of 6 W/Kg over seven days. Compared to the sham and control cage groups, rats exposed to a GSM signal at 6 W/Kg showed decreased CO activity in some areas of the prefrontal and frontal cortex (infralimbic cortex, prelimbic cortex, primary motor cortex, secondary motor cortex, anterior cingulate cortex areas 1 and 2 (Cg1 and Cg2)), the septum (dorsal and ventral parts of the lateral septal nucleus), the hippocampus (dorsal field CA1, CA2 and CA3 of the hippocampus and dental gyrus) and the posterior cortex (retrosplenial agranular cortex, primary and secondary visual cortex, perirhinal cortex and lateral entorhinal cortex). However, the exposure to GSM at 1.5 W/Kg did not affect brain activity. Our results indicate that 6 W/Kg GSM 900 MHz microwaves may affect brain metabolism and neuronal activity in rats.

Delta-9-tetrahydrocannabinol (THC) affects forelimb motor map expression but has little effect on skilled and unskilled behavior.

PubMed

Scullion, K; Guy, A R; Singleton, A; Spanswick, S C; Hill, M N; Teskey, G C

2016-04-05

It has previously been shown in rats that acute administration of delta-9-tetrahydrocannabinol (THC) exerts a dose-dependent effect on simple locomotor activity, with low doses of THC causing hyper-locomotion and high doses causing hypo-locomotion. However the effect of acute THC administration on cortical movement representations (motor maps) and skilled learned movements is completely unknown. It is important to determine the effects of THC on motor maps and skilled learned behaviors because behaviors like driving place people at a heightened risk. Three doses of THC were used in the current study: 0.2mg/kg, 1.0mg/kg and 2.5mg/kg representing the approximate range of the low to high levels of available THC one would consume from recreational use of cannabis. Acute peripheral administration of THC to drug naïve rats resulted in dose-dependent alterations in motor map expression using high resolution short duration intracortical microstimulation (SD-ICMS). THC at 0.2mg/kg decreased movement thresholds and increased motor map size, while 1.0mg/kg had the opposite effect, and 2.5mg/kg had an even more dramatic effect. Deriving complex movement maps using long duration (LD)-ICMS at 1.0mg/kg resulted in fewer complex movements. Dosages of 1.0mg/kg and 2.5mg/kg THC reduced the number of reach attempts but did not affect percentage of success or the kinetics of reaching on the single pellet skilled reaching task. Rats that received 2.5mg/kg THC did show an increase in latency of forelimb removal on the bar task, while dose-dependent effects of THC on unskilled locomotor activity using the rotorod and horizontal ladder tasks were not observed. Rats may be employing compensatory strategies after receiving THC, which may account for the robust changes in motor map expression but moderate effects on behavior. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Intracortical Microstimulation (ICMS) Activates Motor Cortex Layer 5 Pyramidal Neurons Mainly Transsynaptically.

PubMed

Hussin, Ahmed T; Boychuk, Jeffery A; Brown, Andrew R; Pittman, Quentin J; Teskey, G Campbell

2015-01-01

Intracortical microstimulation (ICMS) is a technique used for a number of purposes including the derivation of cortical movement representations (motor maps). Its application can activate the output layer 5 of motor cortex and can result in the elicitation of body movements depending upon the stimulus parameters used. The extent to which pyramidal tract projection neurons of the motor cortex are activated transsynaptically or directly by ICMS remains an open question. Given this uncertainty in the mode of activation, we used a preparation that combined patch clamp whole-cell recordings from single layer 5 pyramidal neurons and extracellular ICMS in slices of motor cortex as well as a standard in vivo mapping technique to ask how ICMS activated motor cortex pyramidal neurons. We measured changes in synaptic spike threshold and spiking rate to ICMS in vitro and movement threshold in vivo in the presence or absence of specific pharmacological blockers of glutamatergic (AMPA, NMDA and Kainate) receptors and GABAA receptors. With major excitatory and inhibitory synaptic transmission blocked (with DNQX, APV and bicuculline methiodide), we observed a significant increase in the ICMS current intensity required to elicit a movement in vivo as well as to the first spike and an 85% reduction in spiking responses in vitro. Subsets of neurons were still responsive after the synaptic block, especially at higher current intensities, suggesting a modest direct activation. Taken together our data indicate a mainly synaptic mode of activation to ICMS in layer 5 of rat motor cortex. Copyright © 2015 Elsevier Inc. All rights reserved.

Is generic physical activity or specific exercise associated with motor abilities?

PubMed

Rinne, Marjo; Pasanen, Matti; Miilunpalo, Seppo; Mälkiä, Esko

2010-09-01

Evidence of the effect of leisure time physical activity (LTPA) modes on the motor abilities of a mature population is scarce. The purpose of this study was to compare the motor abilities of physically active and inactive men and women and to examine the associations of different exercise modes and former and recent LTPA (R-LTPA) with motor ability and various physical tests. The LTPA of the participants (men n = 69, women n = 79; aged 41-47 yr) was ascertained by a modified Physical Activity Readiness Questionnaire, including questions on the frequency, duration, and intensity of R-LTPA and former LTPA and on exercise modes. Motor abilities in terms of balance, agility, and coordination were assessed with a battery of nine tests supplemented with five physical fitness tests. Multiple statistical methods were used in analyses that were conducted separately for men and women. The MET-hours per week of R-LTPA correlated statistically significantly with the tests of agility and static balance (rs = -0.28, P = 0.022; rs = -0.25, P = 0.043, respectively) among men and with the static balance (rs = 0.41), 2-km walking (rs = 0.36), step squat (rs = 0.36) (P < or = 0.001, respectively), and static back endurance (rs = 0.25, P = 0.024) among women. In the stepwise regression among men, the most frequent statistically significant predictor was the playing of several games. For women, a history of LTPA for more than 3 yr was the strongest predictor for good results in almost all tests. Participants with long-term and regular LTPA had better motor performance, and especially a variety of games improve components of motor ability. Diverse, regular, and long-term exercise including both specific training and general activity develops both motor abilities and physical fitness.

Motor system contributions to verbal and non-verbal working memory

PubMed Central

Liao, Diana A.; Kronemer, Sharif I.; Yau, Jeffrey M.; Desmond, John E.; Marvel, Cherie L.

2014-01-01

Working memory (WM) involves the ability to maintain and manipulate information held in mind. Neuroimaging studies have shown that secondary motor areas activate during WM for verbal content (e.g., words or letters), in the absence of primary motor area activation. This activation pattern may reflect an inner speech mechanism supporting online phonological rehearsal. Here, we examined the causal relationship between motor system activity and WM processing by using transcranial magnetic stimulation (TMS) to manipulate motor system activity during WM rehearsal. We tested WM performance for verbalizable (words and pseudowords) and non-verbalizable (Chinese characters) visual information. We predicted that disruption of motor circuits would specifically affect WM processing of verbalizable information. We found that TMS targeting motor cortex slowed response times (RTs) on verbal WM trials with high (pseudoword) vs. low (real word) phonological load. However, non-verbal WM trials were also significantly slowed with motor TMS. WM performance was unaffected by sham stimulation or TMS over visual cortex (VC). Self-reported use of motor strategy predicted the degree of motor stimulation disruption on WM performance. These results provide evidence of the motor system’s contributions to verbal and non-verbal WM processing. We speculate that the motor system supports WM by creating motor traces consistent with the type of information being rehearsed during maintenance. PMID:25309402

Differential suppression of upper airway motor activity during carbachol-induced, REM sleep-like atonia.

PubMed

Fenik, V; Davies, R O; Pack, A I; Kubin, L

1998-10-01

Microinjections of carbachol into the pontine tegmentum of decerebrate cats have been used to study the mechanisms underlying the suppression of postural and respiratory motoneuronal activity during the resulting rapid eye movement (REM) sleep-like atonia. During REM sleep, distinct respiratory muscles are differentially affected; e.g., the activity of the diaphragm shows little suppression, whereas the activity of some upper airway muscles is quite strong. To determine the pattern of the carbachol-induced changes in the activity of different groups of upper airway motoneurons, we simultaneously recorded the efferent activity of the recurrent laryngeal nerve (RL), pharyngeal branch of the vagus nerve (Phar), and genioglossal branch of the hypoglossal (XII) and phrenic (Phr) nerves in 12 decerebrate, paralyzed, vagotomized, and artificially ventilated cats. Pontine carbachol caused a stereotyped suppression of the spontaneous activity that was significantly larger in Phar expiratory (to 8.3% of control) and XII inspiratory motoneurons (to 15%) than in Phr inspiratory (to 87%), RL inspiratory (to 79%), or RL expiratory motoneurons (to 72%). The suppression in upper airway motor output was significantly greater than the depression caused by a level of hypocapnia that reduced Phr activity as much as carbachol. We conclude that pontine carbachol evokes a stereotyped pattern of suppression of upper airway motor activity. Because carbachol evokes a state having many neurophysiological characteristics similar to those of REM sleep, it is likely that pontine cholinoceptive neurons have similar effects on the activity of upper airway motoneurons during both states.

Automatic motor activation in the executive control of action

PubMed Central

McBride, Jennifer; Boy, Frédéric; Husain, Masud; Sumner, Petroc

2012-01-01

Although executive control and automatic behavior have often been considered separate and distinct processes, there is strong emerging and convergent evidence that they may in fact be intricately interlinked. In this review, we draw together evidence showing that visual stimuli cause automatic and unconscious motor activation, and how this in turn has implications for executive control. We discuss object affordances, alien limb syndrome, the visual grasp reflex, subliminal priming, and subliminal triggering of attentional orienting. Consideration of these findings suggests automatic motor activation might form an intrinsic part of all behavior, rather than being categorically different from voluntary actions. PMID:22536177

Complex Regional Pain Syndrome Type I Affects Brain Structure in Prefrontal and Motor Cortex

PubMed Central

Pleger, Burkhard; Draganski, Bogdan; Schwenkreis, Peter; Lenz, Melanie; Nicolas, Volkmar; Maier, Christoph; Tegenthoff, Martin

2014-01-01

The complex regional pain syndrome (CRPS) is a rare but debilitating pain disorder that mostly occurs after injuries to the upper limb. A number of studies indicated altered brain function in CRPS, whereas possible influences on brain structure remain poorly investigated. We acquired structural magnetic resonance imaging data from CRPS type I patients and applied voxel-by-voxel statistics to compare white and gray matter brain segments of CRPS patients with matched controls. Patients and controls were statistically compared in two different ways: First, we applied a 2-sample ttest to compare whole brain white and gray matter structure between patients and controls. Second, we aimed to assess structural alterations specifically of the primary somatosensory (S1) and motor cortex (M1) contralateral to the CRPS affected side. To this end, MRI scans of patients with left-sided CRPS (and matched controls) were horizontally flipped before preprocessing and region-of-interest-based group comparison. The unpaired ttest of the “non-flipped” data revealed that CRPS patients presented increased gray matter density in the dorsomedial prefrontal cortex. The same test applied to the “flipped” data showed further increases in gray matter density, not in the S1, but in the M1 contralateral to the CRPS-affected limb which were inversely related to decreased white matter density of the internal capsule within the ipsilateral brain hemisphere. The gray-white matter interaction between motor cortex and internal capsule suggests compensatory mechanisms within the central motor system possibly due to motor dysfunction. Altered gray matter structure in dorsomedial prefrontal cortex may occur in response to emotional processes such as pain-related suffering or elevated analgesic top-down control. PMID:24416397

Cortical ensemble activity increasingly predicts behaviour outcomes during learning of a motor task

NASA Astrophysics Data System (ADS)

Laubach, Mark; Wessberg, Johan; Nicolelis, Miguel A. L.

2000-06-01

When an animal learns to make movements in response to different stimuli, changes in activity in the motor cortex seem to accompany and underlie this learning. The precise nature of modifications in cortical motor areas during the initial stages of motor learning, however, is largely unknown. Here we address this issue by chronically recording from neuronal ensembles located in the rat motor cortex, throughout the period required for rats to learn a reaction-time task. Motor learning was demonstrated by a decrease in the variance of the rats' reaction times and an increase in the time the animals were able to wait for a trigger stimulus. These behavioural changes were correlated with a significant increase in our ability to predict the correct or incorrect outcome of single trials based on three measures of neuronal ensemble activity: average firing rate, temporal patterns of firing, and correlated firing. This increase in prediction indicates that an association between sensory cues and movement emerged in the motor cortex as the task was learned. Such modifications in cortical ensemble activity may be critical for the initial learning of motor tasks.

Anticholinesterase Effect on Motor Kinematic Measures and Brain Activation in Parkinson’s Disease

PubMed Central

Mentis, Marc J.; Delalot, Dominique; Naqvi, Hassan; Gordon, Mark F.; Gudesblatt, Mark; Edwards, Christine; Donatelli, Luke; Dhawan, Vijay; Eidelberg, David

2015-01-01

Anticholinesterase (AChE) drugs are being prescribed off label for nonmotor symptoms in Parkinson’s disease (PD). Theoretically, these drugs can impair motor function. A small literature suggests AChE therapy has little effect on clinical motor evaluation; however, no study has made objective motor kinematic measures or evaluated brain function. We hypothesized that even if clinical examination was normal in PD patients on dopamine therapy, (1) sensitive kinematic measures would be abnormal during AChE therapy or (2) normal kinematic measures would be maintained by compensatory brain activation. We carried out a randomized, double-blind, placebo-controlled trial of 8 weeks donepezil (10 mg/day) in 17 PD subjects. Subjects carried out a computerized motor task during a positron emission tomography (PET) scan before starting the drug and again after 8 weeks of donepezil or placebo. Kinematic measures of motor function and PET scans were analyzed to compare the effects of donepezil and placebo. Neither placebo nor donepezil altered motor kinematic measures. Furthermore, movement integrity while on donepezil was maintained without compensatory brain activity. Donepezil 10 mg/day can be given for nonmotor symptoms in PD without adverse motor effects or compensatory brain activity. PMID:16228997

Knowledge representation of motor activity of patients with Parkinson's disease.

PubMed

Kostek, Bożena; Kupryjanow, Adam; Czyżewski, Andrzej

An approach to the knowledge representation extraction from biomedical signals analysis concerning motor activity of Parkinson disease patients is proposed in this paper. This is done utilizing accelerometers attached to their body as well as exploiting video image of their hand movements. Experiments are carried out employing artificial neural networks and support vector machine to the recognition of characteristic motor activity disorders in patients. Obtained results indicate that it is possible to interpret some selected patient's body movements with a sufficiently high effectiveness.

Motor development and motor resonance difficulties in autism: relevance to early intervention for language and communication skills

PubMed Central

McCleery, Joseph P.; Elliott, Natasha A.; Sampanis, Dimitrios S.; Stefanidou, Chrysi A.

2013-01-01

Research suggests that a sub-set of children with autism experience notable difficulties and delays in motor skills development, and that a large percentage of children with autism experience deficits in motor resonance. These motor-related deficiencies, which evidence suggests are present from a very early age, are likely to negatively affect social-communicative and language development in this population. Here, we review evidence for delayed, impaired, and atypical motor development in infants and children with autism. We then carefully review and examine the current language and communication-based intervention research that is relevant to motor and motor resonance (i.e., neural “mirroring” mechanisms activated when we observe the actions of others) deficits in children with autism. Finally, we describe research needs and future directions and developments for early interventions aimed at addressing the speech/language and social-communication development difficulties in autism from a motor-related perspective. PMID:23630476

Media use, sports activities, and motor fitness in childhood and adolescence.

PubMed

Kaiser-Jovy, Sebastian; Scheu, Anja; Greier, Klaus

2017-07-01

Physical activity is one of the key determinants of physical, mental, and social health of children and adolescents. Therefore, the early development of health-relevant behavior patterns is of high relevance. To examine the impact of selected socioeconomic factors as well as media consumption, on sports activities and the motor skills of 10- to 14-year-old secondary school students. Body height and body weight were measured. The motor skills were determined with the Deutschen Motorik Test (DMT 6‑18; German Motor Test). Information about media use, media equipment, recreational sports activities, migration status, and the parents' profession was collected by means of a standardized questionnaire. A total of 391 adolescents have been tested (male 235; female 156). Body mass index (BMI) types are evenly distributed on gender. On a weekday, the pupils spend 10.3 h using media (SD ± 9.1 h). On weekends, media use increases up to 12 h per day on average (SD ± 9.7 h). The number of available media is independent from the age of the respondents and the social status of their families. According to bivariate correlations, heavy media use, a high BMI as well as migration status correlate negatively with both sports activities and motor skills. BMI seems to have the strongest influence on athletic performance (b = 0.41). Media use is an important determinant of juvenile sports activity and motor performance, being part of a complex juvenile leisure behavior.

Role of interstitial cells of Cajal in the generation and modulation of motor activity induced by cholinergic neurotransmission in the stomach.

PubMed

Zhang, R-X; Wang, X-Y; Chen, D; Huizinga, J D

2011-09-01

Interstitial cells of Cajal (ICC) are intimately linked to the enteric nervous system and a better understanding of the interactions between the two systems is going to advance our understanding of gut motor control. The objective of the present study was to investigate the role of ICC in the generation of gastric motor activity induced by cholinergic neurotransmission. Gastric motor activity was evoked through activation of intrinsic cholinergic neural activity, in in vitro muscle strips by electrical field stimulation, in the in vitro whole stomach by distension and in vivo by fluoroscopy after gavaging the stomach with barium sulfate. The cholinergic activity was assessed as that component of the effect of the stimulus that was sensitive to atropine. These experiments were carried out in wild-type and Ws/Ws rats that have few intramuscular ICC (ICC-IM) in the stomach. Under all three experimental conditions, cholinergic activity was prominent in both wild-type and W mutant rats providing evidence against the hypothesis that cholinergic neurotransmission to smooth muscle is primarily mediated by ICC-IM. Strong cholinergic activity in Ws/Ws rats was not due to upregulation of muscarinic receptors in ICC but possibly in smooth muscle of the antrum. Pacemaker ICC play a prominent role in the expression of motor activity induced by cholinergic activity and our data suggest that cholinergic neurotransmission to ICC affects the pacemaker frequency. © 2011 Blackwell Publishing Ltd.

Nocturnal motor activity in fibromyalgia patients with poor sleep quality.

PubMed

Hyyppä, M T; Kronholm, E

1995-01-01

Nocturnal motor activity was examined in long-term rehabilitation patients complaining of poor sleep and having fibromyalgia syndrome (N = 24) or other musculoskeletal disorders (N = 60) and compared with that in 91 healthy controls drawn from a random community sample. Self-reports on sleep complaints and habits were collected. The frequency of nocturnal body movements, the "apnoea" index and ratio of "quiet sleep" to total time in bed were measured using the Static Charge Sensitive Bed (SCSB) (BioMatt). As a group, patients with fibromyalgia syndrome did not differ from patients with other musculoskeletal disorders or from healthy controls in their nocturnal motor activity. The "apnoea" index was a little higher in the fibromyalgia group than in the healthy control group but did not differ from that of the group of other musculoskeletal patients. Further multivariate analyses adjusted for age, BMI, medication and "apnoea" index did not support the assumption that an increased nocturnal motor activity characterizes patients with fibromyalgia syndrome.

Association of activity changes in the primary sensory cortex with successful motor rehabilitation of the hand following stroke.

PubMed

Laible, Mona; Grieshammer, Steven; Seidel, Gundula; Rijntjes, Michel; Weiller, Cornelius; Hamzei, Farsin

2012-09-01

Previous studies demonstrated a posterior shift of activation toward the primary sensory cortex (S1) following stroke; however, any relationship between this posterior shift and clinical outcome measures for the affected hand function were unclear. The authors investigated the possible role of S1 in motor recovery. Assuming that previous studies examined inhomogeneous groups of patients, the authors selected participants with chronic stroke who had moderate hand paresis, normal sensory examination and somatosensory-evoked potentials, and no lesion within the S1, thalamus, or brain stem. Constraint-induced movement therapy (CIMT) was used to train the impaired hand. To relate fMRI (functional MRI) activation changes from baseline to post-CIMT, a correlation analysis was performed with changes of the Wolf Motor Function Test (WMFT) as a test for the hand function. A close relationship was found between increases in hand function and peak changes in activation within the ipsilesional S1. With a better outcome, greater increases in activation within the S1 were evident (P < .03; r = 0.73). In selected patients, the sensory network influences training-induced motor gains. This predictive knowledge of plasticity when applying CIMT may suggest strategies to enhance the effect of therapy, such as the addition of electrical stimulation to enhance S1 excitability.

Motorized Activity on Legacy Seismic Lines: A Predictive Modeling Approach to Prioritize Restoration Efforts.

PubMed

Hornseth, M L; Pigeon, K E; MacNearney, D; Larsen, T A; Stenhouse, G; Cranston, J; Finnegan, L

2018-05-11

Natural regeneration of seismic lines, cleared for hydrocarbon exploration, is slow and often hindered by vegetation damage, soil compaction, and motorized human activity. There is an extensive network of seismic lines in western Canada which is known to impact forest ecosystems, and seismic lines have been linked to declines in woodland caribou (Rangifer tarandus caribou). Seismic line restoration is costly, but necessary for caribou conservation to reduce cumulative disturbance. Understanding where motorized activity may be impeding regeneration of seismic lines will aid in prioritizing restoration. Our study area in west-central Alberta, encompassed five caribou ranges where restoration is required under federal species at risk recovery strategies, hence prioritizing seismic lines for restoration is of immediate conservation value. To understand patterns of motorized activity on seismic lines, we evaluated five a priori hypotheses using a predictive modeling framework and Geographic Information System variables across three landscapes in the foothills and northern boreal regions of Alberta. In the northern boreal landscape, motorized activity was most common in dry areas with a large industrial footprint. In highly disturbed areas of the foothills, motorized activity on seismic lines increased with low vegetation heights, relatively dry soils, and further from forest cutblocks, while in less disturbed areas of the foothills, motorized activity on seismic lines decreased proportional to seismic line density, slope steepness, and white-tailed deer abundance, and increased proportional with distance to roads. We generated predictive maps of high motorized activity, identifying 21,777 km of seismic lines where active restoration could expedite forest regeneration.

Promoting gross motor skills and physical activity in childcare: A translational randomized controlled trial.

PubMed

Jones, Rachel A; Okely, Anthony D; Hinkley, Trina; Batterham, Marijka; Burke, Claire

2016-09-01

Educator-led programs for physical activity and motor skill development show potential but few have been implemented and evaluated using a randomized controlled design. Furthermore, few educator-led programs have evaluated both gross motor skills and physical activity. Therefore, the aim of this study was to evaluate a gross motor skill and physical activity program for preschool children which was facilitated solely by childcare educators. A six-month 2-arm randomized controlled trial was implemented between April and September 2012 in four early childhood centers in Tasmania, Australia. Educators participated in ongoing professional development sessions and children participated in structured physical activity lessons and unstructured physical activity sessions. In total, 150 children were recruited from four centers which were randomized to intervention or wait-list control group. Six early childhood educators from the intervention centers were trained to deliver the intervention. Gross motor skills were assessed using the Test of Gross Motor Development (2nd edition) and physical activity was measured objectively using GT3X+ Actigraph accelerometers. No statistically significant differences were identified. However, small to medium effect sizes, in favor of the intervention group, were evident for four of the five gross motor skills and the total gross motor skill score and small to medium effect sizes were reported for all physical activity outcomes. This study highlights the potential of educator-led physical activity interventions and supports the need for further translational trials within the early childhood sector. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Normalizing motor-related brain activity: subthalamic nucleus stimulation in Parkinson disease.

PubMed

Grafton, S T; Turner, R S; Desmurget, M; Bakay, R; Delong, M; Vitek, J; Crutcher, M

2006-04-25

To test whether therapeutic unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) in patients with Parkinson disease (PD) leads to normalization in the pattern of brain activation during movement execution and control of movement extent. Six patients with PD were imaged off medication by PET during performance of a visually guided tracking task with the DBS voltage programmed for therapeutic (effective) or subtherapeutic (ineffective) stimulation. Data from patients with PD during ineffective stimulation were compared with a group of 13 age-matched control subjects to identify sites with abnormal patterns of activation. Conjunction analysis was used to identify those areas in patients with PD where activity normalized when they were treated with effective stimulation. For movement execution, effective DBS caused an increase of activation in the supplementary motor area (SMA), superior parietal cortex, and cerebellum toward a more normal pattern. At rest, effective stimulation reduced overactivity of SMA. Therapeutic stimulation also induced reductions of movement related "overactivity" compared with healthy subjects in prefrontal, temporal lobe, and basal ganglia circuits, consistent with the notion that many areas are recruited to compensate for ineffective motor initiation. Normalization of activity related to the control of movement extent was associated with reductions of activity in primary motor cortex, SMA, and basal ganglia. Effective subthalamic nucleus stimulation leads to task-specific modifications with appropriate recruitment of motor areas as well as widespread, nonspecific reductions of compensatory or competing cortical activity.

Self-regulation of primary motor cortex activity with motor imagery induces functional connectivity modulation: A real-time fMRI neurofeedback study.

PubMed

Makary, Meena M; Seulgi, Eun; Kyungmo Park

2017-07-01

Recent developments in data acquisition of functional magnetic resonance imaging (fMRI) have led to rapid preprocessing and analysis of brain activity in a quasireal-time basis, what so called real-time fMRI neurofeedback (rtfMRI-NFB). This information is fed back to subjects allowing them to gain a voluntary control over their own region-specific brain activity. Forty-one healthy participants were randomized into an experimental (NFB) group, who received a feedback directly proportional to their brain activity from the primary motor cortex (M1), and a control (CTRL) group who received a sham feedback. The M1 ROI was functionally localized during motor execution and imagery tasks. A resting-state functional run was performed before and after the neurofeedback training to investigate the default mode network (DMN) modulation after training. The NFB group revealed increased DMN functional connectivity after training to the cortical and subcortical sensory/motor areas (M1/S1 and caudate nucleus, respectively), which may be associated with sensorimotor processing of learning in the resting state. These results show that motor imagery training through rtfMRI-NFB could modulate the DMN functional connectivity to motor-related areas, suggesting that this modulation potentially subserved the establishment of motor learning in the NFB group.

Non-exercise physical activity attenuates motor symptoms in Parkinson disease independent from nigrostriatal degeneration.

PubMed

Snider, Jonathan; Müller, Martijn L T M; Kotagal, Vikas; Koeppe, Robert A; Scott, Peter J H; Frey, Kirk A; Albin, Roger L; Bohnen, Nicolaas I

2015-10-01

To investigate the relationship between time spent in non-exercise and exercise physical activity and severity of motor functions in Parkinson disease (PD). Increasing motor impairments of PD incline many patients to a sedentary lifestyle. We investigated the relationship between duration of both non-exercise and exercise physical activity over a 4-week period using the Community Health Activities Model Program for Seniors (CHAMPS) questionnaire and severity of clinical motor symptoms in PD. We accounted for the magnitude of nigrostriatal degeneration. Cross-sectional study. PD subjects, n = 48 (40 M); 69.4 ± 7.4 (56-84) years old; 8.4 ± 4.2 (2.5-20) years motor disease duration, mean UPDRS motor score 27.5 ± 10.3 (7-53) and mean MMSE score 28.4 ± 1.9 (22-30) underwent [(11)C]dihydrotetrabenazine (DTBZ) PET imaging to assess nigrostriatal denervation and completed the CHAMPS questionnaire and clinical assessment. Bivariate correlations showed an inverse relationship between motor UPDRS severity scores and duration of non-exercise physical activity (R = -0.37, P = 0.0099) but not with duration of exercise physical activity (R = -0.05, P = 0.76) over 4 weeks. Multiple regression analysis using UPDRS motor score as outcome variable demonstrated a significant regressor effect for duration of non-exercise physical activity (F = 6.15, P = 0.017) while accounting for effects of nigrostriatal degeneration (F = 4.93, P = 0.032), levodopa-equivalent dose (LED; F = 1.07, P = 0.31), age (F = 4.37, P = 0.043) and duration of disease (F = 1.46, P = 0.23; total model (F = 5.76, P = 0.0004). Non-exercise physical activity is a correlate of motor symptom severity in PD independent of the magnitude of nigrostriatal degeneration. Non-exercise physical activity may have positive effects on functional performance in PD. Published by Elsevier Ltd.

Scale dependence of the mechanics of active gels with increasing motor concentration.

PubMed

Sonn-Segev, Adar; Bernheim-Groswasser, Anne; Roichman, Yael

2017-10-18

Actin is a protein that plays an essential role in maintaining the mechanical integrity of cells. In response to strong external stresses, it can assemble into large bundles, but it grows into a fine branched network to induce cell motion. In some cases, the self-organization of actin fibers and networks involves the action of bipolar filaments of the molecular motor myosin. Such self-organization processes mediated by large myosin bipolar filaments have been studied extensively in vitro. Here we create active gels, composed of single actin filaments and small myosin bipolar filaments. The active steady state in these gels persists long enough to enable the characterization of their mechanical properties using one and two point microrheology. We study the effect of myosin concentration on the mechanical properties of this model system for active matter, for two different motor assembly sizes. In contrast to previous studies of networks with large motor assemblies, we find that the fluctuations of tracer particles embedded in the network decrease in amplitude as motor concentration increases. Nonetheless, we show that myosin motors stiffen the actin networks, in accordance with bulk rheology measurements of networks containing larger motor assemblies. This implies that such stiffening is of universal nature and may be relevant to a wider range of cytoskeleton-based structures.

Non-peristaltic patterns of motor activity in the guinea-pig proximal colon.

PubMed

Hennig, G W; Gregory, S; Brookes, S J H; Costa, M

2010-06-01

The guinea-pig proximal colon contains semi-solid feces which are propelled by intermittent neural peristaltic waves to the distal colon, where solid pellets are formed. Between propulsive periods, complex motor patterns underlie fluid re-absorption and mixing of contents. Spatio-temporal analysis of video recordings were used to investigate neural and myogenic patterns of non-peristaltic motor activity. At low distension (6 cmH(2)O), two major motor patterns were seen. Narrow rings of constriction (abrupt contractions) occurred at 19 cpm. These previously undescribed contractions occurred, almost simultaneously, at many points along the preparation, with a calculated propagation velocity of 110 mm s(-1). They were abolished by hexamethonium and by tetrodotoxin, indicating they were neurally mediated. Inhibition of nitric oxide synthase resulted in increased frequency of 'abrupt contractions' suggesting ongoing inhibitory modulation by endogenous nitric oxide. After tetrodotoxin, another distinct motor pattern was revealed; 'ripples'(1) consisted of shallow rings of contraction, occurring at 18 cpm and propagating at 2.7-2.9 mm s(-1) orally or aborally from multiple initiation sites. The frequency of 'ripples' increased as intraluminal pressure was raised, becoming very irregular at high distensions. L-type calcium channel blockers and openers affected the amplitude of 'ripples'. No frequency gradient of 'ripples' along the proximal colon was detected. This absence explains the multiple initiation sites which often shifted over time, and the oral and aboral propagation of 'ripples'. The interaction of myogenic 'ripples' with neurogenic 'abrupt contractions' generates localized alternating rings of contractions and dilatation, well suited to effective mixing of contents.

Ipsilesional motor-evoked potential absence in pediatric hemiparesis impacts tracking accuracy of the less affected hand.

PubMed

Cassidy, Jessica M; Carey, James R; Lu, Chiahao; Krach, Linda E; Feyma, Tim; Durfee, William K; Gillick, Bernadette T

2015-12-01

This study analyzed the relationship between electrophysiological responses to transcranial magnetic stimulation (TMS), finger tracking accuracy, and volume of neural substrate in children with congenital hemiparesis. Nineteen participants demonstrating an ipsilesional motor-evoked potential (MEP) were compared with eleven participants showing an absent ipsilesional MEP response. Comparisons of finger tracking accuracy from the affected and less affected hands and ipsilesional/contralesional (I/C) volume ratio for the primary motor cortex (M1) and posterior limb of internal capsule (PLIC) were done using two-sample t-tests. Participants showing an ipsilesional MEP response demonstrated superior tracking performance from the less affected hand (p=0.016) and significantly higher I/C volume ratios for M1 (p=0.028) and PLIC (p=0.005) compared to participants without an ipsilesional MEP response. Group differences in finger tracking accuracy from the affected hand were not significant. These results highlight differentiating factors amongst children with congenital hemiparesis showing contrasting MEP responses: less affected hand performance and preserved M1 and PLIC volume. Along with MEP status, these factors pose important clinical implications in pediatric stroke rehabilitation. These findings may also reflect competitive developmental processes associated with the preservation of affected hand function at the expense of some function in the less affected hand. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Motor function evaluation in merosin-deficient congenital muscular dystrophy children].

PubMed

Rocco, Fernanda M; Luz, Fernanda H Gianini; Rossato, Alexsander Junquera; Fernandes, Antônio Carlos; Oliveira, Acary S B; Betetas, Javier Toledano; Zanoteli, Edmar

2005-06-01

Congenital muscular dystrophy (CMD) is a heterogeneous group of disorders characterized by early onset of hypotonia and weakness. Almost 50% of the cases are caused by primary deficiency of a protein named merosin (MD), and present a homogenous phenotype with a severe motor and respiratory involvement. Eleven children with clinical and histological diagnosis of CMD-MD, aged of 3 to 15 years, were studied using the manual muscle testing (Medical Research Council), goniometric analysis, motor ability and day life activities (Barthel index) scales, with the objective to characterize the main motor function limitations. The muscular groups most affected were cervical flexors, paravertebral and proximal portions of limbs. The muscular groups of upper limbs were as affected as the lower limbs, and the extensors were more affected than the flexors groups. All children had severe muscular retractions on the hip, knee and elbow. Other frequent deformities were scoliosis and equinus-varum feet. No children presented the motor ability to walk, stand up and crawl; and all of them were classified as dependents or semi-dependents in the day life activities scale. Our findings confirm the severe and diffuse involvement of skeletal muscle in CMD-MD patients, producing serious motor limitations and deformities.

Chemical and thermal modulation of molecular motor activities

NASA Astrophysics Data System (ADS)

Hong, Weili

Molecular motors of kinesin and dynein families are responsible for various intracellular activities, from long distance movement of organelles, vesicles, protein complexes, and mRNAs to powering mitotic processes. They can take nanometer steps using chemical energy from the hydrolysis of ATP (adenosine triphosphate), and their dysfunction is involved in many neurodegenerative diseases that require long distance transport of cargos. Here I report on the study of the properties of molecular motors at a single-molecule level using optical trappings. I first studied the inhibition properties of kinesin motors by marine natural compound adociasulfates. I showed that adociasulfates compete with microtubules for binding to kinesins and thus inhibit kinesins' activity. Although adociasulfates are a strong inhibitor for all kinesin members, they show a much higher inhibition effect for conventional kinesins than for mitotic kinesins. Thus adociasulfates can be used to specifically inhibit conventional kinesins. By comparing the inhibition of kinesins by two structurally similar adociasulfates, one can see that the negatively charged sulfate residue of adociasulfates can be replaced by other negative residues and thus make it possible for adociasulfate-derived compounds to be more cell permeable. Kinesins and dyneins move cargos towards opposite directions along a microtubule. Cargos with both kinesins and dyneins attached often move bidirectionally due to undergoing a tug-of-war between the oppositely moving kinesin and dynein motors. Here I studied the effect of temperature on microtubule-based kinesin and dynein motor transport. While kinesins' and dyneins' velocities are closely matched above 15 °C, below this temperature the dyneins' velocity decreases much faster than the kinesins'. The kinesins' and dyneins' forces do not measurably change with temperature. The results suggest that temperature has significant effects on bidirectional transport and can be used to

Long-lasting involuntary motor activity after spinal cord injury.

PubMed

McKay, W B; Ovechkin, A V; Vitaz, T W; Terson de Paleville, D G L; Harkema, S J

2011-01-01

The study design used is prospective cohort study. This study was designed to neurophysiologically characterize spinal motor activity during recovery from spinal cord injury (SCI). University of Louisville, Louisville, Kentucky, USA. Twenty-five consecutive acute SCI admissions were recruited for this study. The American Spinal Injury Association Impairment Scale (AIS) was used to categorize injury level and severity at onset. Surface EMG recording was carried out initially between the day of admission and 17 days post-onset (6.0 ± 4.3, mean ± s.d. days). Follow-up recordings were performed for up to 9 months after injury. Initial AIS distribution was 7 AIS-A; 3 AIS-B; 2 AIS-C; 13 AIS-D. Twelve subjects (48%) showed long-duration involuntary motor-unit activation during relaxation. This activity was seen on initial examination in nine and on follow-up by 3 months post-injury in three others. It was seen in muscles innervated from the injury zone in 11 and caudal to the lesion in 9 subjects. This activity was independent of the presence or absence of tendon reflexes and the ability to volitionally suppress plantar stimulation elicited reflex withdrawal. The form of involuntary activity described here is the likely result of the altered balance of excitation and inhibition reaching spinal motor neurons because of the loss of inhibitory interneurons or their reduced activation by damaged supraspinal drive and the synaptic reorganization that follows SCI. As such, this activity may be useful for monitoring the effects of neuroprotective and restorative intervention strategies in persons with SCI.

Long-lasting Involuntary Motor Activity After Spinal Cord Injury

PubMed Central

McKay, WB; Ovechkin, AV; Vitaz, TW; de Paleville, DGLTerson; Harkema, SJ

2010-01-01

Study Design Prospective cohort study Objective This study was designed to neurophysiologically characterize spinal motor activity during recovery from spinal cord injury (SCI). Setting University of Louisville, Louisville, Kentucky, USA. Material Twenty five consecutive acute SCI admissions were recruited for this study. Methods The American Spinal Injury Association Impairment Scale (AIS) was used to categorize injury level and severity at onset. Surface EMG recording, was carried out initially between the day of admission and 17 days post onset (6.0 ± 4.3, mean ± SD days). Follow-up recordings were performed for up to 9 months after injury. Initial AIS distribution was: 7 AIS-A; 3 AIS-B; 2 AIS-C; 13 AIS-D. Results Twelve subjects (48%) showed long-duration involuntary motor unit activation during relaxation. This activity was seen on initial examination in nine and on follow-up by three months post-injury in three others. It was seen in muscles innervated from the injury zone in 11 and caudal to the lesion in 9 subjects. This activity was independent of the presence or absence of tendon reflexes and the ability to volitionally suppress plantar stimulation elicited reflex withdrawal. Conclusions The form of involuntary activity described here is the likely result of the altered balance of excitation and inhibition reaching spinal motor neurons due to the loss of inhibitory interneurons or their reduced activation by damaged supraspinal drive and the synaptic reorganization that follows SCI. As such, this activity may be useful for monitoring the effects of neuroprotective and restorative intervention strategies in persons with SCI. PMID:20585326

Altered neuronal activities in the motor cortex with impaired motor performance in adult rats observed after infusion of cerebrospinal fluid from amyotrophic lateral sclerosis patients.

PubMed

Sankaranarayani, R; Nalini, A; Rao Laxmi, T; Raju, T R

2010-01-05

Although definite evidences are available to state that, neuronal activity is a prime determinant of animal behavior, the specific relationship between local field potentials of the motor cortex after intervention with CSF from human patients and animal behavior have remained opaque. The present study has investigated whether cerebrospinal fluid from sporadic amyotrophic lateral sclerosis (sALS) patients could disrupt neuronal activity of the motor cortex, which could be associated with disturbances in the motor performance of adult rats. CSF from ALS patients (ALS-CSF) was infused into the lateral ventricle of Wistar rats. After 24h, the impact of ALS-CSF on the local field potentials (LFPs) of the motor cortex and on the motor behavior of animals were examined. The results indicate that ALS-CSF produced a bivariate distribution on the relative power values of the LFPs of the motor cortex 24h following infusion. However, the behavioral results did not show bimodality, instead showed consistent decrease in motor performance: on rotarod and grip strength meter. The neuronal activity of the motor cortex negatively correlated with the duration of ALS symptoms at the time of lumbar puncture. Although the effect of ALS-CSF was more pronounced at 24h following infusion, the changes observed in LFPs and motor performance appeared to revert to baseline values at later time points of testing. In the current study, we have shown that, ALS-CSF has the potential to perturb neuronal activity of the rat motor cortex which was associated with poor performance on motor function tests.

Motor and Nonmotor Circuitry Activation Induced by Subthalamic Nucleus Deep Brain Stimulation in Patients With Parkinson Disease: Intraoperative Functional Magnetic Resonance Imaging for Deep Brain Stimulation.

PubMed

Knight, Emily J; Testini, Paola; Min, Hoon-Ki; Gibson, William S; Gorny, Krzysztof R; Favazza, Christopher P; Felmlee, Joel P; Kim, Inyong; Welker, Kirk M; Clayton, Daniel A; Klassen, Bryan T; Chang, Su-youne; Lee, Kendall H

2015-06-01

To test the hypothesis suggested by previous studies that subthalamic nucleus (STN) deep brain stimulation (DBS) in patients with Parkinson disease would affect the activity of motor and nonmotor networks, we applied intraoperative functional magnetic resonance imaging (fMRI) to patients receiving DBS. Ten patients receiving STN DBS for Parkinson disease underwent intraoperative 1.5-T fMRI during high-frequency stimulation delivered via an external pulse generator. The study was conducted between January 1, 2013, and September 30, 2014. We observed blood oxygen level-dependent (BOLD) signal changes (false discovery rate <0.001) in the motor circuitry (including the primary motor, premotor, and supplementary motor cortices; thalamus; pedunculopontine nucleus; and cerebellum) and in the limbic circuitry (including the cingulate and insular cortices). Activation of the motor network was observed also after applying a Bonferroni correction (P<.001) to the data set, suggesting that across patients, BOLD changes in the motor circuitry are more consistent compared with those occurring in the nonmotor network. These findings support the modulatory role of STN DBS on the activity of motor and nonmotor networks and suggest complex mechanisms as the basis of the efficacy of this treatment modality. Furthermore, these results suggest that across patients, BOLD changes in the motor circuitry are more consistent than those in the nonmotor network. With further studies combining the use of real-time intraoperative fMRI with clinical outcomes in patients treated with DBS, functional imaging techniques have the potential not only to elucidate the mechanisms of DBS functioning but also to guide and assist in the surgical treatment of patients affected by movement and neuropsychiatric disorders. clinicaltrials.gov Identifier: NCT01809613. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

The Longitudinal Course of Gross Motor Activity in Schizophrenia – Within and between Episodes

PubMed Central

Walther, Sebastian; Stegmayer, Katharina; Horn, Helge; Rampa, Luca; Razavi, Nadja; Müller, Thomas J.; Strik, Werner

2015-01-01

Schizophrenia is associated with heterogeneous course of positive and negative symptoms. In addition, reduced motor activity as measured by wrist actigraphy has been reported. However, longitudinal studies of spontaneous motor activity are missing. We aimed to explore whether activity levels were stable within and between psychotic episodes. Furthermore, we investigated the association with the course of negative symptoms. In 45 medicated patients, we investigated motor behavior within a psychotic episode. In addition, we followed 18 medicated patients across 2 episodes. Wrist actigraphy and psychopathological ratings were applied. Within an episode symptoms changed but activity levels did not vary systematically. Activity at baseline predicted the course of negative symptoms. Between two episodes activity recordings were much more stable. Again, activity at the index episode predicted the outcome of negative symptoms. In sum, spontaneous motor activity shares trait and state characteristics, the latter are associated with negative symptom course. Actigraphy may therefore become an important ambulatory instrument to monitor negative symptoms and treatment outcome in schizophrenia. PMID:25698981

Gross Motor Activities: Movement for Fun and Learning.

ERIC Educational Resources Information Center

Lowenthal, Barbara

1983-01-01

Examples are provided of ways in which gross motor activities are integrated into mathematics, language arts, social studies, art, and music and creative movement concepts for preschool- and primary-age children with special needs. (CL)

Methylphenidate-induced motor activity in rats: modulation by melatonin and vasopressin.

PubMed

Appenrodt, Edgar; Schwarzberg, Helmut

2003-04-01

Methylphenidate (MPH), a dopamine (DA) reuptake inhibitor, is well known to enhance motor activity, in part depending on the time of its application during the light-dark cycle. Moreover, after MPH administration, the hypothalamo-neurohypophysial axis including the neuropeptide vasopressin (AVP) was found influenced. Both the latter and behavioural effects of central AVP can also be modulated by the pineal gland with its light-dark-dependent activity. The present study was performed to investigate whether the pineal gland, its hormone melatonin (Mel), and AVP are involved in the MPH-evoked stimulation of activity. After application of 10 mg/kg MPH, the motor activity in pinealectomised (PE) rats was significantly higher than in sham-operated (SO) animals. After application of 250 microg Mel before MPH treatment, the stimulation of motor activity was diminished in PE rats and augmented in SO animals; however, when SO and PE rats were compared after Mel pretreatment, the reaction to MPH was nearly identical. Blocking the endogenous AVP by 25 or 1 microg of the V1a receptor antagonist d(CH(2))(5)[Tyr(Me)(2)]AVP (AAVP) before MPH treatment significantly augmented the motor activity in SO rats only and abolished the differences seen between SO and PE animals after MPH application. The present results indicate that the behavioural stimulation of MPH was modulated by both the pineal gland with its hormone Mel as well as the neuropeptide AVP.

Effect of the Children's Health Activity Motor Program on Motor Skills and Self-Regulation in Head Start Preschoolers: An Efficacy Trial.

PubMed

Robinson, Leah E; Palmer, Kara K; Bub, Kristen L

2016-01-01

Self-regulatory skills are broadly defined as the ability to manage emotions, focus attention, and inhibit some behaviors while activating others in accordance with social expectations and are an established indicator of academic success. Growing evidence links motor skills and physical activity to self-regulation. This study examined the efficacy of a motor skills intervention (i.e., the Children's Health Activity Motor Program, CHAMP) that is theoretically grounded in Achievement Goal Theory on motor skill performance and self-regulation in Head Start preschoolers. A sample of 113 Head Start preschoolers (Mage = 51.91 ± 6.5 months; 49.5% males) were randomly assigned to a treatment (n = 68) or control (n = 45) program. CHAMP participants engaged in 15, 40-min sessions of a mastery climate intervention that focused on the development of motor skills over 5 weeks while control participants engaged in their normal outdoor recess period. The Delay of Gratification Snack Task was used to measure self-regulation and the Test of Gross Motor Development-2nd Edition was used to assess motor skills. All measures were assessed prior to and following the intervention. Linear mixed models were fit for both self-regulation and motor skills. Results revealed a significant time × treatment interaction (p < 0.001). In regard to motor skills, post hoc comparisons found that all children improved their motor skills (p < 0.05), but the CHAMP group improved significantly more than the control group (p < 0.001). Children in CHAMP maintained their self-regulation scores across time, while children in the control group scored significantly lower than the CHAMP group at the posttest (p < 0.05). CHAMP is a mastery climate movement program that enhance skills associated with healthy development in children (i.e., motor skills and self-regulation). This efficacy trial provided evidence that CHAMP helped maintain delay of gratification in preschool

Tissue Plasminogen Activator Induction in Purkinje Neurons After Cerebellar Motor Learning

NASA Astrophysics Data System (ADS)

Seeds, Nicholas W.; Williams, Brian L.; Bickford, Paula C.

1995-12-01

The cerebellar cortex is implicated in the learning of complex motor skills. This learning may require synaptic remodeling of Purkinje cell inputs. An extracellular serine protease, tissue plasminogen activator (tPA), is involved in remodeling various nonneural tissues and is associated with developing and regenerating neurons. In situ hybridization showed that expression of tPA messenger RNA was increased in the Purkinje neurons of rats within an hour of their being trained for a complex motor task. Antibody to tPA also showed the induction of tPA protein associated with cerebellar Purkinje cells. Thus, the induction of tPA during motor learning may play a role in activity-dependent synaptic plasticity.

Factors affecting outcome of triceps motor branch transfer for isolated axillary nerve injury.

PubMed

Lee, Joo-Yup; Kircher, Michelle F; Spinner, Robert J; Bishop, Allen T; Shin, Alexander Y

2012-11-01

Triceps motor branch transfer has been used in upper brachial plexus injury and is potentially effective for isolated axillary nerve injury in lieu of sural nerve grafting. We evaluated the functional outcome of this procedure and determined factors that influenced the outcome. A retrospective chart review was performed of 21 patients (mean age, 38 y; range, 16-79 y) who underwent triceps motor branch transfer for the treatment of isolated axillary nerve injury. Deltoid muscle strength was evaluated using the modified British Medical Research Council grading at the last follow-up (mean, 21 mo; range, 12-41 mo). The following variables were analyzed to determine whether they affected the outcome of the nerve transfer: the age and sex of the patient, delay from injury to surgery, body mass index (BMI), severity of trauma, and presence of rotator cuff lesions. The Spearman correlation coefficient and multiple linear regression were performed for statistical analysis. The average Medical Research Council grade of deltoid muscle strength was 3.5 ± 1.1. Deltoid muscle strength correlated with the age of the patient, delay from injury to surgery, and BMI of the patient. Five patients failed to achieve more than M3 grade. Among them, 4 patients were older than 50 years and 1 was treated 14 months after injury. In the multiple linear regression model, the delay from injury to surgery, age of the patient, and BMI of the patient were the important factors, in that order, that affected the outcome of this procedure. Isolated axillary nerve injury can be treated successfully with triceps motor branch transfer. However, outstanding outcomes are not universal, with one fourth failing to achieve M3 strength. The outcome of this procedure is affected by the delay from injury to surgery and the age and BMI of the patient. Copyright © 2012 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Hyperactivity and Motoric Activity in ADHD: Characterization, Assessment, and Intervention

PubMed Central

Gawrilow, Caterina; Kühnhausen, Jan; Schmid, Johanna; Stadler, Gertraud

2014-01-01

The aim of the present literature review is threefold. (1) We will review theories, models, and studies on symptomatic hyperactivity and motoric activity in attention-deficit/hyperactivity disorder (ADHD). (2) Another focus will be on assessment methods that have been proven to be effective in the detection of hyperactivity and motoric activity in children, adolescents, and adults with and without ADHD and emerging areas of research in the field of ADHD. We will compare subjective methods (i.e., rating scales) and objective methods (i.e., accelerometers). (3) Finally, physical activity intervention studies aiming at a modification of activity and overactive behavior will be summarized that seem to be promising candidates for alleviating hyperactivity symptoms in children, adolescents, and adults with ADHD. PMID:25506329

Sub-lethal effects of the neurotoxic pyrethroid insecticide Fastac 50EC on the general motor and locomotor activities of the non-targeted beneficial carabid beetle Platynus assimilis (Coleoptera: Carabidae).

PubMed

Tooming, Ene; Merivee, Enno; Must, Anne; Sibul, Ivar; Williams, Ingrid

2014-06-01

Sub-lethal effects of pesticides on behavioural endpoints are poorly studied in carabids (Coleoptera: Carabidae) though changes in behaviour caused by chemical stress may affect populations of these non-targeted beneficial insects. General motor activity and locomotion are inherent in many behavioural patterns, and changes in these activities that result from xenobiotic influence mirror an integrated response of the insect to pesticides. Influence of pyrethroid insecticides over a wide range of sub-lethal doses on the motor activities of carabids still remains unclear. Video tracking of Platynus assimilis showed that brief exposure to alpha-cypermethrin at sub-lethal concentrations ranged from 0.01 to 100 mg L(-1) caused initial short-term (< 2 h) locomotor hyperactivity followed by a long-term (>24 h) locomotor hypo-activity. In addition, significant short- and long-term concentration and time-dependent changes occurred in general motor activity patterns and rates. Conspicuous changes in motor activity of Platynus assimilis beetles treated at alpha-cypermethrin concentrations up to 75,000-fold lower than maximum field recommended concentration (MFRC) suggest that many, basic fitness-related behaviours might be severely injured as well. These changes may negatively affect carabid populations in agro-ecosystems. Long-term hypo-activity could directly contribute to decreased trap captures of carabids frequently observed after insecticide application in the field. © 2013 Society of Chemical Industry.

Effect of high-fat intake on motor activity, homovanillic acid and 5-hydroxyindoleacetic acid levels in striatum and cortex of rats exposed to stress.

PubMed

Kirac, Deniz; Ozden, Inci; Yildirim, Alper; Genç, Ece

2009-04-01

The aim of the present study was to investigate whether high fat consumption changes the effects of stress on both motor activity performance, striatal and cortical dopamine and serotonin metabolites in rats. The animals were fed either with high fat or standard diet for 4 weeks. Restraint stress lasting for 15 min at +4 degrees C was applied daily to stress-exposed groups. Motor activity performance was measured weekly by using motor activity monitoring systems. At the end of the study, homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) levels of the striatum and cerebral cortex were measured by HPLCEC. It was observed that restraint stress increased locomotor activity and high-fat diet prevented this effect. Stress and high-fat intake had an additive decreasing effect on striatal HVA levels. 5-HIAA levels, on the other hand, were lower in both high fat and high fat + stress groups compared to the stress group. These results suggest that high-fat intake differentially affected the stress response on striatal dopaminergic and serotonergic neurons in rat brain regions studied and this may be related to the effects observed in motor activity performance.

Spindles and active vortices in a model of confined filament-motor mixtures.

PubMed

Head, David A; Briels, Wj; Gompper, Gerhard

2011-11-16

Robust self-organization of subcellular structures is a key principle governing the dynamics and evolution of cellular life. In fission yeast cells undergoing division, the mitotic spindle spontaneously emerges from the interaction of microtubules, motor proteins and the confining cell walls, and asters and vortices have been observed to self-assemble in quasi-two dimensional microtubule-kinesin assays. There is no clear microscopic picture of the role of the active motors driving this pattern formation, and the relevance of continuum modeling to filament-scale structures remains uncertain. Here we present results of numerical simulations of a discrete filament-motor protein model confined to a pressurised cylindrical box. Stable spindles, nematic configurations, asters and high-density semi-asters spontaneously emerge, the latter pair having also been observed in cytosol confined within emulsion droplets. State diagrams are presented delineating each stationary state as the pressure, motor speed and motor density are varied. We further highlight a parameter regime where vortices form exhibiting collective rotation of all filaments, but have a finite life-time before contracting to a semi-aster. Quantifying the distribution of life-times suggests this contraction is a Poisson process. Equivalent systems with fixed volume exhibit persistent vortices with stochastic switching in the direction of rotation, with switching times obeying similar statistics to contraction times in pressurised systems. Furthermore, we show that increasing the detachment rate of motors from filament plus-ends can both destroy vortices and turn some asters into vortices. We have shown that discrete filament-motor protein models provide new insights into the stationary and dynamical behavior of active gels and subcellular structures, because many phenomena occur on the length-scale of single filaments. Based on our findings, we argue the need for a deeper understanding of the microscopic

White matter microstructure and volitional motor activity in schizophrenia: A diffusion kurtosis imaging study.

PubMed

Docx, Lise; Emsell, Louise; Van Hecke, Wim; De Bondt, Timo; Parizel, Paul M; Sabbe, Bernard; Morrens, Manuel

2017-02-28

Avolition is a core feature of schizophrenia and may arise from altered brain connectivity. Here we used diffusion kurtosis imaging (DKI) to investigate the association between white matter (WM) microstructure and volitional motor activity. Multi-shell diffusion MRI and 24-h actigraphy data were obtained from 20 right-handed patients with schizophrenia and 16 right-handed age and gender matched healthy controls. We examined correlations between fractional anisotropy (FA), mean diffusivity (MD), mean kurtosis (MK), and motor activity level, as well as group differences in these measures. In the patient group, increasing motor activity level was positively correlated with MK in the inferior, medial and superior longitudinal fasciculus, the corpus callosum, the posterior fronto-occipital fasciculus and the posterior cingulum. This association was not found in control subjects or in DTI measures. These results show that a lack of volitional motor activity in schizophrenia is associated with potentially altered WM microstructure in posterior brain regions associated with cognitive function and motivation. This could reflect both illness related dysconnectivity which through altered cognition, manifests as reduced volitional motor activity, and/or the effects of reduced physical activity on brain WM. Copyright © 2016. Published by Elsevier B.V.

Impact of Auditory Context on Executed Motor Actions

PubMed Central

Yoles-Frenkel, Michal; Avron, Maayan; Prut, Yifat

2016-01-01

The auditory and motor systems are strongly coupled, as is evident in the specifically tight motor synchronization that occurs in response to regularly occurring auditory cues compared with cues of other modalities. Timing of rhythmic action is known to rely on multiple neural centers including the cerebellum and the basal-ganglia which have access to both motor cortical and spinal circuitries. To date, however, there is little information on the motor mechanisms that operate during preparation and execution of rhythmic vs. non-rhythmic movements. We measured acceleration profile and muscle activity while subjects performed tapping movements in response to auditory cues. We found that when tapping at random intervals there was a higher variability of both acceleration profile and muscle activity during motor preparation compared to rhythmic tapping. However, the specific rhythmic context (cued, self-paced, or syncopation) did not affect the motor parameters of the executed taps. Finally, during entrainment we found a gradual as opposed to episodic change in low-level motor parameters (i.e., preparatory muscle activity) that was strongly correlated with changes in high-level parameters (i.e., shift in the reaction time to negative asynchrony). These findings suggest that motor entrainment involves not only adjusting the timing of movement but also modifying parameters that are related to its production. These changes in motor output were insensitive to the specifics of the rhythmic cue: although it took subjects different times to become entrained to different types of rhythmic cues, the motor actions produced once entrainment was obtained were indistinguishable. These findings suggest that motor entrainment involves not only adjusting the timing of movement but also modifying parameters related to its production. The reduced variability of muscle activity during the preparatory period could be one mechanism used by the motor system to enhance the accuracy of motor

Network of movement and proximity sensors for monitoring upper-extremity motor activity after stroke: proof of principle.

PubMed

Sokal, Brad; Uswatte, Gitendra; Barman, Joydip; Brewer, Michael; Byrom, Ezekiel; Latten, Jessica; Joseph, Jeethu; Serafim, Camila; Ghaffari, Touraj; Sarkar, Nilanjan

2014-03-01

To test the convergent validity of an objective method, Sensor-Enabled Radio-frequency Identification System for Monitoring Arm Activity (SERSMAA), that distinguishes between functional and nonfunctional activity. Cross-sectional study. Laboratory. Participants (N=25) were ≥0.2 years poststroke (median, 9) with a wide range of severity of upper-extremity hemiparesis. Not applicable. After stroke, laboratory tests of the motor capacity of the more-affected arm poorly predict spontaneous use of that arm in daily life. However, available subjective methods for measuring everyday arm use are vulnerable to self-report biases, whereas available objective methods only provide information on the amount of activity without regard to its relation with function. The SERSMAA consists of a proximity-sensor receiver on the more-affected arm and multiple units placed on objects. Functional activity is signaled when the more-affected arm is close to an object that is moved. Participants were videotaped during a laboratory simulation of an everyday activity, that is, setting a table with cups, bowls, and plates instrumented with transmitters. Observers independently coded the videos in 2-second blocks with a validated system for classifying more-affected arm activity. There was a strong correlation (r=.87, P<.001) between time that the more-affected arm was used for handling objects according to the SERSMAA and functional activity according to the observers. The convergent validity of SERSMAA for measuring more-affected arm functional activity after stroke was supported in a simulation of everyday activity. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Non-exercise physical activity attenuates motor symptoms in Parkinson disease independent from nigrostriatal degeneration

PubMed Central

Snider, Jon; Müller, Martijn L.T.M; Kotagal, Vikas; Koeppe, Robert A; Scott, Peter J.H.; Frey, Kirk A; Albin, Roger L.; Bohnen, Nicolaas I.

2015-01-01

Objective To investigate the relationship between time spent in non-exercise and exercise physical activity and severity of motor functions in Parkinson disease (PD). Background Increasing motor impairments of PD incline many patients to a sedentary lifestyle. We investigated the relationship between duration of both non-exercise and exercise physical activity over a 4-week period using the Community Health Activities Model Program for Seniors (CHAMPS) questionnaire and severity of clinical motor symptoms in PD. We accounted for the magnitude of nigrostriatal degeneration. Methods Cross-sectional study. PD subjects, n=48 (40M); 69.4±7.4 (56–84) years old; 8.4±4.2 (2.5–20) years motor disease duration, mean UPDRS motor score 27.5 ± 10.3 (7–53) and mean MMSE score 28.4 ± 1.9 (22–30) underwent [11C]dihydrotetrabenazine (DTBZ) PET imaging to assess nigrostriatal denervation and completed the CHAMPS questionnaire and clinical assessment. Results Bivariate correlations showed an inverse relationship between motor UPDRS severity scores and duration of non-exercise physical activity (R= −0.37, P=0.0099) but not with duration of exercise physical activity (R= −0.05, P= 0.76) over 4 weeks. Multiple regression analysis using UPDRS motor score as outcome variable demonstrated a significant regressor effect for duration of non-exercise physical activity (F=6.15, P=0.017) while accounting for effects of nigrostriatal degeneration (F=4.93, P=0.032), levodopa-equivalent dose (LED; F=1.07, P=0.31), age (F=4.37, P=0.043) and duration of disease (F=1.46, P=0.23; total model (F=5.76, P=0.0004). Conclusions Non-exercise physical activity is a correlate of motor symptom severity in PD independent of the magnitude of nigrostriatal degeneration. Non-exercise physical activity may have positive effects on functional performance in PD. PMID:26330028

Motor training and physical activity among preschoolers with cerebral palsy: a survey of parents' experiences.

PubMed

Myrhaug, Hilde Tinderholt; Østensjø, Sigrid

2014-05-01

To describe motor training and physical activity among preschoolers with cerebral palsy (CP) in Norway, and assess associations between child, parent, and motor intervention characteristics, and parent-reported child benefits from interventions. Survey of 360 parents and data from the Norwegian CP follow-up program. The response rate was 34%. During the six months preceding the time of the survey, 75% of the children performed gross-motor training, 73% fine-motor training, 80% manual stretching, and 67% participated regularly in physical activities. The training was highly goal-directed, intensive, frequently incorporated in daily routines, and often with a high level of parental involvement. The use of goals was associated with higher parent-reported child benefits for all types of interventions. Moreover, the positive relationship, which was indicated between frequency of training, parent education, and parent-reported child benefits of gross-motor training, was not seen for fine-motor training. Parent-reported child benefits support goal-directed motor interventions, and the use of everyday activities to increase practice of motor skills.

Resting-state functional connectivity and motor imagery brain activation

PubMed Central

Saiote, Catarina; Tacchino, Andrea; Brichetto, Giampaolo; Roccatagliata, Luca; Bommarito, Giulia; Cordano, Christian; Battaglia, Mario; Mancardi, Giovanni Luigi; Inglese, Matilde

2016-01-01

Motor imagery (MI) relies on the mental simulation of an action without any overt motor execution (ME), and can facilitate motor learning and enhance the effect of rehabilitation in patients with neurological conditions. While functional magnetic resonance imaging (fMRI) during MI and ME reveals shared cortical representations, the role and functional relevance of the resting-state functional connectivity (RSFC) of brain regions involved in MI is yet unknown. Here, we performed resting-state fMRI followed by fMRI during ME and MI with the dominant hand. We used a behavioral chronometry test to measure ME and MI movement duration and compute an index of performance (IP). Then, we analyzed the voxel-matched correlation between the individual MI parameter estimates and seed-based RSFC maps in the MI network to measure the correspondence between RSFC and MI fMRI activation. We found that inter-individual differences in intrinsic connectivity in the MI network predicted several clusters of activation. Taken together, present findings provide first evidence that RSFC within the MI network is predictive of the activation of MI brain regions, including those associated with behavioral performance, thus suggesting a role for RSFC in obtaining a deeper understanding of neural substrates of MI and of MI ability. PMID:27273577

Processing abstract language modulates motor system activity.

PubMed

Glenberg, Arthur M; Sato, Marc; Cattaneo, Luigi; Riggio, Lucia; Palumbo, Daniele; Buccino, Giovanni

2008-06-01

Embodiment theory proposes that neural systems for perception and action are also engaged during language comprehension. Previous neuroimaging and neurophysiological studies have only been able to demonstrate modulation of action systems during comprehension of concrete language. We provide neurophysiological evidence for modulation of motor system activity during the comprehension of both concrete and abstract language. In Experiment 1, when the described direction of object transfer or information transfer (e.g., away from the reader to another) matched the literal direction of a hand movement used to make a response, speed of responding was faster than when the two directions mismatched (an action-sentence compatibility effect). In Experiment 2, we used single-pulse transcranial magnetic stimulation to study changes in the corticospinal motor pathways to hand muscles while reading the same sentences. Relative to sentences that do not describe transfer, there is greater modulation of activity in the hand muscles when reading sentences describing transfer of both concrete objects and abstract information. These findings are discussed in relation to the human mirror neuron system.

Effect of the Children’s Health Activity Motor Program on Motor Skills and Self-Regulation in Head Start Preschoolers: An Efficacy Trial

PubMed Central

Robinson, Leah E.; Palmer, Kara K.; Bub, Kristen L.

2016-01-01

Self-regulatory skills are broadly defined as the ability to manage emotions, focus attention, and inhibit some behaviors while activating others in accordance with social expectations and are an established indicator of academic success. Growing evidence links motor skills and physical activity to self-regulation. This study examined the efficacy of a motor skills intervention (i.e., the Children’s Health Activity Motor Program, CHAMP) that is theoretically grounded in Achievement Goal Theory on motor skill performance and self-regulation in Head Start preschoolers. A sample of 113 Head Start preschoolers (Mage = 51.91 ± 6.5 months; 49.5% males) were randomly assigned to a treatment (n = 68) or control (n = 45) program. CHAMP participants engaged in 15, 40-min sessions of a mastery climate intervention that focused on the development of motor skills over 5 weeks while control participants engaged in their normal outdoor recess period. The Delay of Gratification Snack Task was used to measure self-regulation and the Test of Gross Motor Development-2nd Edition was used to assess motor skills. All measures were assessed prior to and following the intervention. Linear mixed models were fit for both self-regulation and motor skills. Results revealed a significant time × treatment interaction (p < 0.001). In regard to motor skills, post hoc comparisons found that all children improved their motor skills (p < 0.05), but the CHAMP group improved significantly more than the control group (p < 0.001). Children in CHAMP maintained their self-regulation scores across time, while children in the control group scored significantly lower than the CHAMP group at the posttest (p < 0.05). CHAMP is a mastery climate movement program that enhance skills associated with healthy development in children (i.e., motor skills and self-regulation). This efficacy trial provided evidence that CHAMP helped maintain delay of gratification in preschool

Advances in selective activation of muscles for non-invasive motor neuroprostheses.

PubMed

Koutsou, Aikaterini D; Moreno, Juan C; Del Ama, Antonio J; Rocon, Eduardo; Pons, José L

2016-06-13

Non-invasive neuroprosthetic (NP) technologies for movement compensation and rehabilitation remain with challenges for their clinical application. Two of those major challenges are selective activation of muscles and fatigue management. This review discusses how electrode arrays improve the efficiency and selectivity of functional electrical stimulation (FES) applied via transcutaneous electrodes. In this paper we review the principles and achievements during the last decade on techniques for artificial motor unit recruitment to improve the selective activation of muscles. We review the key factors affecting the outcome of muscle force production via multi-pad transcutaneous electrical stimulation and discuss how stimulation parameters can be set to optimize external activation of body segments. A detailed review of existing electrode array systems proposed by different research teams is also provided. Furthermore, a review of the targeted applications of existing electrode arrays for control of upper and lower limb NPs is provided. Eventually, last section demonstrates the potential of electrode arrays to overcome the major challenges of NPs for compensation and rehabilitation of patient-specific impairments.

Comparison of Environmental Interactions and Motor Activity of Visually Handicapped and Sighted Children.

ERIC Educational Resources Information Center

Schneekloth, Lynda H.; Day, Diane

The study compared the motor activities and environmental interactions of 36 sighted, partially sighted, and blind children (7 to 13 years old) during unstructured play. Objectives were to assess motor proficiency level; to establish frequency and kind of gross motor, manipulative self stimulation, and social/play behaviors; and to assess use of…

Complementary interactions between command-like interneurons that function to activate and specify motor programs.

PubMed

Wu, Jin-Sheng; Wang, Nan; Siniscalchi, Michael J; Perkins, Matthew H; Zheng, Yu-Tong; Yu, Wei; Chen, Song-an; Jia, Ruo-nan; Gu, Jia-Wei; Qian, Yi-Qing; Ye, Yang; Vilim, Ferdinand S; Cropper, Elizabeth C; Weiss, Klaudiusz R; Jing, Jian

2014-05-07

Motor activity is often initiated by a population of command-like interneurons. Command-like interneurons that reliably drive programs have received the most attention, so little is known about how less reliable command-like interneurons may contribute to program generation. We study two electrically coupled interneurons, cerebral-buccal interneuron-2 (CBI-2) and CBI-11, which activate feeding motor programs in the mollusk Aplysia californica. Earlier work indicated that, in rested preparations, CBI-2, a powerful activator of programs, can trigger ingestive and egestive programs. CBI-2 reliably generated ingestive patterns only when it was repeatedly stimulated. The ability of CBI-2 to trigger motor activity has been attributed to the two program-promoting peptides it contains, FCAP and CP2. Here, we show that CBI-11 differs from CBI-2 in that it contains FCAP but not CP2. Furthermore, it is weak in its ability to drive programs. On its own, CBI-11 is therefore less effective as a program activator. When it is successful, however, CBI-11 is an effective specifier of motor activity; that is, it drives mostly ingestive programs. Importantly, we found that CBI-2 and CBI-11 complement each other's actions. First, prestimulation of CBI-2 enhanced the ability of CBI-11 to drive programs. This effect appears to be partly mediated by CP2. Second, coactivation of CBI-11 with CBI-2 makes CBI-2 programs immediately ingestive. This effect may be mediated by specific actions that CBI-11 exerts on pattern-generating interneurons. Therefore, different classes of command-like neurons in a motor network may make distinct, but potentially complementary, contributions as either activators or specifiers of motor activity.

Complementary Interactions between Command-Like Interneurons that Function to Activate and Specify Motor Programs

PubMed Central

Wu, Jin-Sheng; Wang, Nan; Siniscalchi, Michael J.; Perkins, Matthew H.; Zheng, Yu-Tong; Yu, Wei; Chen, Song-an; Jia, Ruo-nan; Gu, Jia-Wei; Qian, Yi-Qing; Ye, Yang; Vilim, Ferdinand S.; Cropper, Elizabeth C.; Weiss, Klaudiusz R.

2014-01-01

Motor activity is often initiated by a population of command-like interneurons. Command-like interneurons that reliably drive programs have received the most attention, so little is known about how less reliable command-like interneurons may contribute to program generation. We study two electrically coupled interneurons, cerebral-buccal interneuron-2 (CBI-2) and CBI-11, which activate feeding motor programs in the mollusk Aplysia californica. Earlier work indicated that, in rested preparations, CBI-2, a powerful activator of programs, can trigger ingestive and egestive programs. CBI-2 reliably generated ingestive patterns only when it was repeatedly stimulated. The ability of CBI-2 to trigger motor activity has been attributed to the two program-promoting peptides it contains, FCAP and CP2. Here, we show that CBI-11 differs from CBI-2 in that it contains FCAP but not CP2. Furthermore, it is weak in its ability to drive programs. On its own, CBI-11 is therefore less effective as a program activator. When it is successful, however, CBI-11 is an effective specifier of motor activity; that is, it drives mostly ingestive programs. Importantly, we found that CBI-2 and CBI-11 complement each other's actions. First, prestimulation of CBI-2 enhanced the ability of CBI-11 to drive programs. This effect appears to be partly mediated by CP2. Second, coactivation of CBI-11 with CBI-2 makes CBI-2 programs immediately ingestive. This effect may be mediated by specific actions that CBI-11 exerts on pattern-generating interneurons. Therefore, different classes of command-like neurons in a motor network may make distinct, but potentially complementary, contributions as either activators or specifiers of motor activity. PMID:24806677

Task-Relevant Information Modulates Primary Motor Cortex Activity Before Movement Onset.

PubMed

Calderon, Cristian B; Van Opstal, Filip; Peigneux, Philippe; Verguts, Tom; Gevers, Wim

2018-01-01

Monkey neurophysiology research supports the affordance competition hypothesis (ACH) proposing that cognitive information useful for action selection is integrated in sensorimotor areas. In this view, action selection would emerge from the simultaneous representation of competing action plans, in parallel biased by relevant task factors. This biased competition would take place up to primary motor cortex (M1). Although ACH is plausible in environments affording choices between actions, its relevance for human decision making is less clear. To address this issue, we designed an functional magnetic resonance imaging (fMRI) experiment modeled after monkey neurophysiology studies in which human participants processed cues conveying predictive information about upcoming button presses. Our results demonstrate that, as predicted by the ACH, predictive information (i.e., the relevant task factor) biases activity of primary motor regions. Specifically, first, activity before movement onset in contralateral M1 increases as the competition is biased in favor of a specific button press relative to activity in ipsilateral M1. Second, motor regions were more tightly coupled with fronto-parietal regions when competition between potential actions was high, again suggesting that motor regions are also part of the biased competition network. Our findings support the idea that action planning dynamics as proposed in the ACH are valid both in human and non-human primates.

Motor Skill Development in Italian Pre-School Children Induced by Structured Activities in a Specific Playground.

PubMed

Tortella, Patrizia; Haga, Monika; Loras, Håvard; Sigmundsson, Hermundur; Fumagalli, Guido

2016-01-01

This study examined the effects and specificity of structured and unstructured activities played at the playground Primo Sport 0246 in Northern Italy on motor skill competence in five years old children. The playground was specifically designed to promote gross motor skills in preschool children; in this study 71 children from local kindergartens came to the park once a week for ten consecutive weeks and were exposed to 30 minutes of free play and 30 minutes of structured activities. Before and after the ten visits, each child completed nine tests to assess levels of motor skills, three for fine-motor skills and six for gross-motor skills. As control, motor skills were also assessed on 39 children from different kindergartens who did not come to the park. The results show that the experimental group who practiced gross-motor activities in the playground for 1 hour a week for 10 weeks improved significantly in 4 out of the 6 gross motor tasks and in none of the fine motor tasks. The data indicate that limited transfer occurred between tasks referring to different domains of motor competences while suggesting cross feeding for improvement of gross-motor skills between different exercises when domains related to physical fitness and strength of specific muscle groups are involved. These results are relevant to the issue of condition(s) appropriate for maintaining and developing motor skills in this age group as well as for the planning, organization and implementation of play and physical activities in kindergartens.

Motor Skill Development in Italian Pre-School Children Induced by Structured Activities in a Specific Playground

PubMed Central

Tortella, Patrizia; Haga, Monika; Loras, Håvard

2016-01-01

This study examined the effects and specificity of structured and unstructured activities played at the playground Primo Sport 0246 in Northern Italy on motor skill competence in five years old children. The playground was specifically designed to promote gross motor skills in preschool children; in this study 71 children from local kindergartens came to the park once a week for ten consecutive weeks and were exposed to 30 minutes of free play and 30 minutes of structured activities. Before and after the ten visits, each child completed nine tests to assess levels of motor skills, three for fine-motor skills and six for gross-motor skills. As control, motor skills were also assessed on 39 children from different kindergartens who did not come to the park. The results show that the experimental group who practiced gross-motor activities in the playground for 1 hour a week for 10 weeks improved significantly in 4 out of the 6 gross motor tasks and in none of the fine motor tasks. The data indicate that limited transfer occurred between tasks referring to different domains of motor competences while suggesting cross feeding for improvement of gross-motor skills between different exercises when domains related to physical fitness and strength of specific muscle groups are involved. These results are relevant to the issue of condition(s) appropriate for maintaining and developing motor skills in this age group as well as for the planning, organization and implementation of play and physical activities in kindergartens. PMID:27462985

Modulation of genioglossus muscle activity across sleep-wake states by histamine at the hypoglossal motor pool.

PubMed

Bastedo, Timothy; Chan, Erin; Park, Eileen; Liu, Hattie; Horner, Richard L

2009-10-01

Histamine neurons comprise a major component of the aminergic arousal system and significantly influence sleep-wake states, with antihistamines widely used as sedative hypnotics. Unlike the serotonergic and noradrenergic components of this arousal system, however, the role of histamine in the central control of respiratory motor activity has not been determined. The aims of this study were to characterize the effects of histamine receptor agonists and antagonists at the hypoglossal motor pool on genioglossus muscle activity across sleep and awake states, and also determine if histamine contributes an endogenous excitatory drive to modulate hypoglossal motor outflow to genioglossus muscle. Thirty-three rats were implanted with electroencephalogram and neck electrodes to record sleep-wake states, and genioglossus and diaphragm electrodes for respiratory muscle recordings. Microdialysis probes were inserted into the hypoglossal motor nucleus. Histamine at the hypoglossal motor nucleus significantly increased tonic genioglossus muscle activity in wakefulness, non-REM sleep and REM sleep. The activating effects of histamine on genioglossus muscle activity also occurred with a histamine type-1 (H1) but not H2 receptor agonist. However, H1 receptor antagonism at the hypoglossal motor nucleus did not decrease genioglossus muscle activity in wakefulness or sleep. The results suggest that histamine at the hypoglossal motor pool increases genioglossus muscle activity in freely behaving rats in wakefulness, non-REM, and REM sleep via an H1 receptor mechanism.

Drosophila non-muscle myosin II motor activity determines the rate of tissue folding

PubMed Central

Vasquez, Claudia G; Heissler, Sarah M; Billington, Neil; Sellers, James R; Martin, Adam C

2016-01-01

Non-muscle cell contractility is critical for tissues to adopt shape changes. Although, the non-muscle myosin II holoenzyme (myosin) is a molecular motor that powers contraction of actin cytoskeleton networks, recent studies have questioned the importance of myosin motor activity cell and tissue shape changes. Here, combining the biochemical analysis of enzymatic and motile properties for purified myosin mutants with in vivo measurements of apical constriction for the same mutants, we show that in vivo constriction rate scales with myosin motor activity. We show that so-called phosphomimetic mutants of the Drosophila regulatory light chain (RLC) do not mimic the phosphorylated RLC state in vitro. The defect in the myosin motor activity in these mutants is evident in developing Drosophila embryos where tissue recoil following laser ablation is decreased compared to wild-type tissue. Overall, our data highlights that myosin activity is required for rapid cell contraction and tissue folding in developing Drosophila embryos. DOI: http://dx.doi.org/10.7554/eLife.20828.001 PMID:28035903

Early functional MRI activation predicts motor outcome after ischemic stroke: a longitudinal, multimodal study.

PubMed

Du, Juan; Yang, Fang; Zhang, Zhiqiang; Hu, Jingze; Xu, Qiang; Hu, Jianping; Zeng, Fanyong; Lu, Guangming; Liu, Xinfeng

2018-05-15

An accurate prediction of long term outcome after stroke is urgently required to provide early individualized neurorehabilitation. This study aimed to examine the added value of early neuroimaging measures and identify the best approaches for predicting motor outcome after stroke. This prospective study involved 34 first-ever ischemic stroke patients (time since stroke: 1-14 days) with upper limb impairment. All patients underwent baseline multimodal assessments that included clinical (age, motor impairment), neurophysiological (motor-evoked potentials, MEP) and neuroimaging (diffusion tensor imaging and motor task-based fMRI) measures, and also underwent reassessment 3 months after stroke. Bivariate analysis and multivariate linear regression models were used to predict the motor scores (Fugl-Meyer assessment, FMA) at 3 months post-stroke. With bivariate analysis, better motor outcome significantly correlated with (1) less initial motor impairment and disability, (2) less corticospinal tract injury, (3) the initial presence of MEPs, (4) stronger baseline motor fMRI activations. In multivariate analysis, incorporating neuroimaging data improved the predictive accuracy relative to only clinical and neurophysiological assessments. Baseline fMRI activation in SMA was an independent predictor of motor outcome after stroke. A multimodal model incorporating fMRI and clinical measures best predicted the motor outcome following stroke. fMRI measures obtained early after stroke provided independent prediction of long-term motor outcome.

Motor priming in virtual reality can augment motor-imagery training efficacy in restorative brain-computer interaction: a within-subject analysis.

PubMed

Vourvopoulos, Athanasios; Bermúdez I Badia, Sergi

2016-08-09

The use of Brain-Computer Interface (BCI) technology in neurorehabilitation provides new strategies to overcome stroke-related motor limitations. Recent studies demonstrated the brain's capacity for functional and structural plasticity through BCI. However, it is not fully clear how we can take full advantage of the neurobiological mechanisms underlying recovery and how to maximize restoration through BCI. In this study we investigate the role of multimodal virtual reality (VR) simulations and motor priming (MP) in an upper limb motor-imagery BCI task in order to maximize the engagement of sensory-motor networks in a broad range of patients who can benefit from virtual rehabilitation training. In order to investigate how different BCI paradigms impact brain activation, we designed 3 experimental conditions in a within-subject design, including an immersive Multimodal Virtual Reality with Motor Priming (VRMP) condition where users had to perform motor-execution before BCI training, an immersive Multimodal VR condition, and a control condition with standard 2D feedback. Further, these were also compared to overt motor-execution. Finally, a set of questionnaires were used to gather subjective data on Workload, Kinesthetic Imagery and Presence. Our findings show increased capacity to modulate and enhance brain activity patterns in all extracted EEG rhythms matching more closely those present during motor-execution and also a strong relationship between electrophysiological data and subjective experience. Our data suggest that both VR and particularly MP can enhance the activation of brain patterns present during overt motor-execution. Further, we show changes in the interhemispheric EEG balance, which might play an important role in the promotion of neural activation and neuroplastic changes in stroke patients in a motor-imagery neurofeedback paradigm. In addition, electrophysiological correlates of psychophysiological responses provide us with valuable information

Motor unit recruitment and bursts of activity in the surface electromyogram during a sustained contraction.

PubMed

Riley, Zachary A; Terry, Mary E; Mendez-Villanueva, Alberto; Litsey, Jane C; Enoka, Roger M

2008-06-01

Bursts of activity in the surface electromyogram (EMG) during a sustained contraction have been interpreted as corresponding to the transient recruitment of motor units, but this association has never been confirmed. The current study compared the timing of trains of action potentials discharged by single motor units during a sustained contraction with the bursts of activity detected in the surface EMG signal. The 20 motor units from 6 subjects [recruitment threshold, 35.3 +/- 11.3% maximal voluntary contraction (MVC) force] that were detected with fine wire electrodes discharged 2-9 trains of action potentials (7.2 +/- 5.6 s in duration) when recruited during a contraction that was sustained at a force below its recruitment threshold (target force, 25.4 +/- 10.6% MVC force). High-pass filtering the bipolar surface EMG signal improved its correlation with the single motor unit signal. An algorithm applied to the surface EMG was able to detect 75% of the trains of motor unit action potentials. The results indicate that bursts of activity in the surface EMG during a constant-force contraction correspond to the transient recruitment of higher-threshold motor units in healthy individuals, and these results could assist in the diagnosis and design of treatment in individuals who demonstrate deficits in motor unit activation.

ACUTE EFFECTS OF AMITRAZ ON THE ACOUSTIC STARTLE RESPONSE AND MOTOR ACTIVITY

EPA Science Inventory

To characterize further the behavioral toxicity of amitraz, comparisons were made between the effects of amitraz on motor activity, the acoustic startle response, body temperature, and body weight in male Long-Evans rats. cute dosage-effect and time-course determinations of motor...

Primary motor cortex activity reduction under the regulation of SMA by real-time fMRI

NASA Astrophysics Data System (ADS)

Guo, Jia; Zhao, Xiaojie; Li, Yi; Yao, Li; Chen, Kewei

2012-03-01

Real-time fMRI (rtfMRI) is a new technology which allows human subjects to observe and control their own BOLD signal change from one or more localized brain regions during scanning. Current rtfMRI-neurofeedback studies mainly focused on the target region itself without considering other related regions influenced by the real-time feedback. However, there always exits important directional influence between many of cooperative regions. On the other hand, rtfMRI based on motor imagery mainly aimed at somatomotor cortex or primary motor area, whereas supplement motor area (SMA) was a relatively more integrated and pivotal region. In this study, we investigated whether the activities of SMA can be controlled utilizing different motor imagery strategies, and whether there exists any possible impact on an unregulated but related region, primary motor cortex (M1). SMA was first localized using overt finger tapping task, the activities of SMA were feedback to subjects visually on line during each of two subsequent imagery motor movement sessions. All thirteen healthy participants were found to be able to successfully control their SMA activities by self-fit imagery strategies which involved no actual motor movements. The activation of right M1 was also found to be significantly reduced in both intensity and extent with the neurofeedback process targeted at SMA, suggestive that not only the part of motor cortex activities were influenced under the regulation of a key region SMA, but also the increased difference between SMA and M1 might reflect the potential learning effect.

Distinct alterations in motor & reward seeking behavior are dependent on the gestational age of exposure to LPS-induced maternal immune activation.

PubMed

Straley, Megan E; Van Oeffelen, Wesley; Theze, Sarah; Sullivan, Aideen M; O'Mahony, Siobhain M; Cryan, John F; O'Keeffe, Gerard W

2017-07-01

The dopaminergic system is involved in motivation, reward and the associated motor activities. Mesodiencephalic dopaminergic neurons in the ventral tegmental area (VTA) regulate motivation and reward, whereas those in the substantia nigra (SN) are essential for motor control. Defective VTA dopaminergic transmission has been implicated in schizophrenia, drug addiction and depression whereas dopaminergic neurons in the SN are lost in Parkinson's disease. Maternal immune activation (MIA) leading to in utero inflammation has been proposed to be a risk factor for these disorders, yet it is unclear how this stimulus can lead to the diverse disturbances in dopaminergic-driven behaviors that emerge at different stages of life in affected offspring. Here we report that gestational age is a critical determinant of the subsequent alterations in dopaminergic-driven behavior in rat offspring exposed to lipopolysaccharide (LPS)-induced MIA. Behavioral analysis revealed that MIA on gestational day 16 but not gestational day 12 resulted in biphasic impairments in motor behavior. Specifically, motor impairments were evident in early life, which were resolved by adolescence, but subsequently re-emerged in adulthood. In contrast, reward seeking behaviors were altered in offspring exposed MIA on gestational day 12. These changes were not due to a loss of dopaminergic neurons per se in the postnatal period, suggesting that they reflect functional changes in dopaminergic systems. This highlights that gestational age may be a key determinant of how MIA leads to distinct alterations in dopaminergic-driven behavior across the lifespan of affected offspring. Copyright © 2016 Elsevier Inc. All rights reserved.

T & I--Electric Motors. Kit No. 621. Instructor's Manual and Student Learning Activity Guide.

ERIC Educational Resources Information Center

Bomar, William

This instructor's manual and student learning activity guide comprise a kit for trade and industrial education (T & I) activities on electric motors. Purpose stated for the activities is to teach the student the four basic types of electric motors, the advantages and disadvantages of each, the types of jobs each can perform, and how to disassemble…

3D visualization of movements can amplify motor cortex activation during subsequent motor imagery.

PubMed

Sollfrank, Teresa; Hart, Daniel; Goodsell, Rachel; Foster, Jonathan; Tan, Tele

2015-01-01

A repetitive movement practice by motor imagery (MI) can influence motor cortical excitability in the electroencephalogram (EEG). This study investigated if a realistic visualization in 3D of upper and lower limb movements can amplify motor related potentials during subsequent MI. We hypothesized that a richer sensory visualization might be more effective during instrumental conditioning, resulting in a more pronounced event related desynchronization (ERD) of the upper alpha band (10-12 Hz) over the sensorimotor cortices thereby potentially improving MI based brain-computer interface (BCI) protocols for motor rehabilitation. The results show a strong increase of the characteristic patterns of ERD of the upper alpha band components for left and right limb MI present over the sensorimotor areas in both visualization conditions. Overall, significant differences were observed as a function of visualization modality (VM; 2D vs. 3D). The largest upper alpha band power decrease was obtained during MI after a 3-dimensional visualization. In total in 12 out of 20 tasks the end-user of the 3D visualization group showed an enhanced upper alpha ERD relative to 2D VM group, with statistical significance in nine tasks.With a realistic visualization of the limb movements, we tried to increase motor cortex activation during subsequent MI. The feedback and the feedback environment should be inherently motivating and relevant for the learner and should have an appeal of novelty, real-world relevance or aesthetic value (Ryan and Deci, 2000; Merrill, 2007). Realistic visual feedback, consistent with the participant's MI, might be helpful for accomplishing successful MI and the use of such feedback may assist in making BCI a more natural interface for MI based BCI rehabilitation.

Enhancing Motor Network Activity Using Real-Time Functional MRI Neurofeedback of Left Premotor Cortex

PubMed Central

Marins, Theo F.; Rodrigues, Erika C.; Engel, Annerose; Hoefle, Sebastian; Basílio, Rodrigo; Lent, Roberto; Moll, Jorge; Tovar-Moll, Fernanda

2015-01-01

Neurofeedback by functional magnetic resonance imaging (fMRI) is a technique of potential therapeutic relevance that allows individuals to be aware of their own neurophysiological responses and to voluntarily modulate the activity of specific brain regions, such as the premotor cortex (PMC), important for motor recovery after brain injury. We investigated (i) whether healthy human volunteers are able to up-regulate the activity of the left PMC during a right hand finger tapping motor imagery (MI) task while receiving continuous fMRI-neurofeedback, and (ii) whether successful modulation of brain activity influenced non-targeted motor control regions. During the MI task, participants of the neurofeedback group (NFB) received ongoing visual feedback representing the level of fMRI responses within their left PMC. Control (CTL) group participants were shown similar visual stimuli, but these were non-contingent on brain activity. Both groups showed equivalent levels of behavioral ratings on arousal and MI, before and during the fMRI protocol. In the NFB, but not in CLT group, brain activation during the last run compared to the first run revealed increased activation in the left PMC. In addition, the NFB group showed increased activation in motor control regions extending beyond the left PMC target area, including the supplementary motor area, basal ganglia and cerebellum. Moreover, in the last run, the NFB group showed stronger activation in the left PMC/inferior frontal gyrus when compared to the CTL group. Our results indicate that modulation of PMC and associated motor control areas can be achieved during a single neurofeedback-fMRI session. These results contribute to a better understanding of the underlying mechanisms of MI-based neurofeedback training, with direct implications for rehabilitation strategies in severe brain disorders, such as stroke. PMID:26733832

Enduring effects of post-weaning rearing condition on depressive- and anxiety-like behaviors and motor activity in male rats.

PubMed

Mosaferi, Belal; Babri, Shirin; Ebrahimi, Hadi; Mohaddes, Gisou

2015-04-01

Environmental manipulation at early critical periods could have long-lasting effects. In spite of the great interest in the biological effects of the environmental condition so far, its long-lasting effects are less documented. This study looks at the enduring effects of rearing condition on tasks that measure affective responses and exploratory behavior in male Wistar rats. The animals were reared from weaning to adulthood in an enriched environment, standard laboratory condition, or isolated condition. Then, all rats were housed in standard laboratory cages to provide a common environment, and successively exposed to different tests between 0 and 11 weeks post-manipulation. The open field test indicated a more efficient exploratory behavior in the enriched group, and an enhanced spontaneous motor activity in both standard and isolated groups. In addition, rats reared in standard condition showed heightened motor activity in forced swimming test and elevated plus maze. Forced swimming test showed an antidepressive-like effect in the enriched environment group by increased climbing behavior. In respect to the anxiety behavior, environmental enrichment improved threat detection ability. It is concluded that rearing condition from weaning to adulthood has important and long-lasting effects on depressive- and anxiety-like and exploratory behaviors as well as motor activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Muscle activation described with a differential equation model for large ensembles of locally coupled molecular motors.

PubMed

Walcott, Sam

2014-10-01

Molecular motors, by turning chemical energy into mechanical work, are responsible for active cellular processes. Often groups of these motors work together to perform their biological role. Motors in an ensemble are coupled and exhibit complex emergent behavior. Although large motor ensembles can be modeled with partial differential equations (PDEs) by assuming that molecules function independently of their neighbors, this assumption is violated when motors are coupled locally. It is therefore unclear how to describe the ensemble behavior of the locally coupled motors responsible for biological processes such as calcium-dependent skeletal muscle activation. Here we develop a theory to describe locally coupled motor ensembles and apply the theory to skeletal muscle activation. The central idea is that a muscle filament can be divided into two phases: an active and an inactive phase. Dynamic changes in the relative size of these phases are described by a set of linear ordinary differential equations (ODEs). As the dynamics of the active phase are described by PDEs, muscle activation is governed by a set of coupled ODEs and PDEs, building on previous PDE models. With comparison to Monte Carlo simulations, we demonstrate that the theory captures the behavior of locally coupled ensembles. The theory also plausibly describes and predicts muscle experiments from molecular to whole muscle scales, suggesting that a micro- to macroscale muscle model is within reach.

Cortical activity predicts good variation in human motor output.

PubMed

Babikian, Sarine; Kanso, Eva; Kutch, Jason J

2017-04-01

Human movement patterns have been shown to be particularly variable if many combinations of activity in different muscles all achieve the same task goal (i.e., are goal-equivalent). The nervous system appears to automatically vary its output among goal-equivalent combinations of muscle activity to minimize muscle fatigue or distribute tissue loading, but the neural mechanism of this "good" variation is unknown. Here we use a bimanual finger task, electroencephalography (EEG), and machine learning to determine if cortical signals can predict goal-equivalent variation in finger force output. 18 healthy participants applied left and right index finger forces to repeatedly perform a task that involved matching a total (sum of right and left) finger force. As in previous studies, we observed significantly more variability in goal-equivalent muscle activity across task repetitions compared to variability in muscle activity that would not achieve the goal: participants achieved the task in some repetitions with more right finger force and less left finger force (right > left) and in other repetitions with less right finger force and more left finger force (left > right). We found that EEG signals from the 500 milliseconds (ms) prior to each task repetition could make a significant prediction of which repetitions would have right > left and which would have left > right. We also found that cortical maps of sites contributing to the prediction contain both motor and pre-motor representation in the appropriate hemisphere. Thus, goal-equivalent variation in motor output may be implemented at a cortical level.

Effectiveness, active energy produced by molecular motors, and nonlinear capacitance of the cochlear outer hair cell.

PubMed

Spector, Alexander A

2005-06-01

Cochlear outer hair cells are crucial for active hearing. These cells have a unique form of motility, named electromotility, whose main features are the cell's length changes, active force production, and nonlinear capacitance. The molecular motor, prestin, that drives outer hair cell electromotility has recently been identified. We reveal relationships between the active energy produced by the outer hair cell molecular motors, motor effectiveness, and the capacitive properties of the cell membrane. We quantitatively characterize these relationships by introducing three characteristics: effective capacitance, zero-strain capacitance, and zero-resultant capacitance. We show that zero-strain capacitance is smaller than zero-resultant capacitance, and that the effective capacitance is between the two. It was also found that the differences between the introduced capacitive characteristics can be expressed in terms of the active energy produced by the cell's molecular motors. The effectiveness of the cell and its molecular motors is introduced as the ratio of the motors'active energy to the energy of the externally applied electric field. It is shown that the effectiveness is proportional to the difference between zero-strain and zero-resultant capacitance. We analyze the cell and motor's effectiveness within a broad range of cellular parameters and estimate it to be within a range of 12%-30%.

Motor neuron mitochondrial dysfunction in spinal muscular atrophy

PubMed Central

Miller, Nimrod; Shi, Han; Zelikovich, Aaron S.; Ma, Yong-Chao

2016-01-01

Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, predominantly affects high metabolic tissues including motor neurons, skeletal muscles and the heart. Although the genetic cause of SMA has been identified, mechanisms underlying tissue-specific vulnerability are not well understood. To study these mechanisms, we carried out a deep sequencing analysis of the transcriptome of spinal motor neurons in an SMA mouse model, in which we unexpectedly found changes in many genes associated with mitochondrial bioenergetics. Importantly, functional measurement of mitochondrial activities showed decreased basal and maximal mitochondrial respiration in motor neurons from SMA mice. Using a reduction-oxidation sensitive GFP and fluorescence sensors specifically targeted to mitochondria, we found increased oxidative stress level and impaired mitochondrial membrane potential in motor neurons affected by SMA. In addition, mitochondrial mobility was impaired in SMA disease conditions, with decreased retrograde transport but no effect on anterograde transport. We also found significantly increased fragmentation of the mitochondrial network in primary motor neurons from SMA mice, with no change in mitochondria density. Electron microscopy study of SMA mouse spinal cord revealed mitochondria fragmentation, edema and concentric lamellar inclusions in motor neurons affected by the disease. Intriguingly, these functional and structural deficiencies in the SMA mouse model occur during the presymptomatic stage of disease, suggesting a role in initiating SMA. Altogether, our findings reveal a critical role for mitochondrial defects in SMA pathogenesis and suggest a novel target for improving tissue health in the disease. PMID:27488123

Hand motor activity, cognition, mood, and the rest-activity rhythm in dementia: a clustered RCT.

PubMed

Eggermont, Laura H P; Knol, Dirk L; Hol, Elly M; Swaab, Dick F; Scherder, Erik J A

2009-01-23

Physical activity such as walking may exert a positive impact on cognition and behaviour in older persons with dementia, but due to the frailty of the population it may be worthwhile to consider other motor activities as well. Examining the effects of hand motor activity on cognition, mood and the rest-activity rhythm in older persons with dementia. Sixty-one older nursing home residents with dementia (mean age 84.6 years) were randomly assigned to either a hand movement program (experimental) or read aloud program (control) for 30min, 5 days a week, during 6 weeks. Neuropsychological tests, mood questionnaires, and actigraphy data were assessed at baseline, after 6 weeks, and again after 6 weeks. Apolipoprotein epsilon (ApoE) genotype was determined. Scores on neuropsychological tests were combined and formed specific Cognitive domains. Symptoms of depression and anxiety formed the Mood domain. Actigraphy variables composed the Rest-activity domain. In mixed model analyses no significant group x time interactions were found on either the Cognitive, Mood or Rest-activity domains in the intention-to-treat analysis. In the per protocol analysis, that included people who attended at least 80% of the sessions, mood improved only in the experimental group. No significant time x group x ApoE interaction effects were found in either analysis. In older nursing home residents with dementia, increased attendance to the hand movement program appeared to have a positive effect on mood. Hand motor activity is a type of activity that can be applied at a large scale.

Discharges of aortic and carotid sinus baroreceptors during spontaneous motor activity and pharmacologically evoked pressor interventions.

PubMed

Matsukawa, Kanji; Ishii, Kei; Kadowaki, Akito; Ishida, Tomoko; Idesako, Mitsuhiro; Liang, Nan

2014-07-01

Our laboratory has demonstrated that the cardiomotor component of aortic baroreflex is temporarily inhibited at the onset of spontaneous motor activity in decerebrate cats, without altering carotid sinus baroreflex. A reason for this dissociation may be attributed to a difference in the responses between aortic nerve activity (AoNA) and carotid sinus nerve activity (CsNA) during spontaneous motor activity. The stimulus-response curves of AoNA and CsNA against mean arterial blood pressure (MAP) were compared between the pressor interventions evoked by spontaneous motor activity and by intravenous administration of phenylephrine or norepinephrine, in which the responses in heart rate (HR) were opposite (i.e., tachycardia vs. baroreflex bradycardia), despite the identical increase in MAP of 34-40 mmHg. In parallel to the pressor response, mean AoNA and CsNA increased similarly by 78-81 and by 88 % of the baseline control, respectively, irrespective of whether the pressor response was evoked by spontaneous motor activity or by a pharmacological intervention. The slope of the stimulus-response curve of the mean AoNA became greater (P < 0.05) during spontaneous motor activity as compared to the pharmacological intervention. On the other hand, the stimulus-response curve of the mean CsNA and its slope were equal (P > 0.05) between the two pressor interventions. Furthermore, the slopes of the stimulus-response curves of both diastolic AoNA and CsNA (defined as the minimal value within a beat) exhibited a greater increase during spontaneous motor activity. All differences in the slopes of the stimulus-response curves were abolished by restraining HR at the intrinsic cardiac frequency. In conclusion, mean mass activities of both aortic and carotid sinus baroreceptors are able to encode the beat-by-beat changes in MAP not only at rest but also during spontaneous motor activity and spontaneous motor activity-related reduction of aortic baroreceptor activity is denied

Neural activity underlying motor-action preparation and cognitive narrowing in approach-motivated goal states.

PubMed

Gable, Philip A; Threadgill, A Hunter; Adams, David L

2016-02-01

High-approach-motivated (pre-goal) positive affect states encourage tenacious goal pursuit and narrow cognitive scope. As such, high approach-motivated states likely enhance the neural correlates of motor-action preparation to aid in goal acquisition. These neural correlates may also relate to the cognitive narrowing associated with high approach-motivated states. In the present study, we investigated motor-action preparation during pre-goal and post-goal states using an index of beta suppression over the motor cortex. The results revealed that beta suppression was greatest in pre-goal positive states, suggesting that higher levels of motor-action preparation occur during high approach-motivated positive states. Furthermore, beta and alpha suppression in the high approach-motivated positive states predicted greater cognitive narrowing. These results suggest that approach-motivated pre-goal states engage the neural substrates of motor-action preparation and cognitive narrowing. Individual differences in motor-action preparation relate to the degree of cognitive narrowing.

EEG activation differences in the pre-motor cortex and supplementary motor area between normal individuals with high and low traits of autism.

PubMed

Puzzo, Ignazio; Cooper, Nicholas R; Vetter, Petra; Russo, Riccardo

2010-06-25

The human mirror neuron system (hMNS) is believed to provide a basic mechanism for social cognition. Event-related desynchronization (ERD) in alpha (8-12Hz) and low beta band (12-20Hz) over sensori-motor cortex has been suggested to index mirror neurons' activity. We tested whether autistic traits revealed by high and low scores on the Autistic Quotient (AQ) in the normal population are linked to variations in the electroencephalogram (EEG) over motor, pre-motor cortex and supplementary motor area (SMA) during action observation. Results revealed that in the low AQ group, the pre-motor cortex and SMA were more active during hand action than static hand observation whereas in the high AQ group the same areas were active both during static and hand action observation. In fact participants with high traits of autism showed greater low beta ERD while observing the static hand than those with low traits and this low beta ERD was not significantly different when they watched hand actions. Over primary motor cortex, the classical alpha and low beta ERD during hand actions relative to static hand observation was found across all participants. These findings suggest that the observation-execution matching system works differently according to the degree of autism traits in the normal population and that this is differentiated in terms of the EEG according to scalp site and bandwidth. Copyright 2010 Elsevier B.V. All rights reserved.

Emergence of gamma motor activity in an artificial neural network model of the corticospinal system.

PubMed

Grandjean, Bernard; Maier, Marc A

2017-02-01

Muscle spindle discharge during active movement is a function of mechanical and neural parameters. Muscle length changes (and their derivatives) represent its primary mechanical, fusimotor drive its neural component. However, neither the action nor the function of fusimotor and in particular of γ-drive, have been clearly established, since γ-motor activity during voluntary, non-locomotor movements remains largely unknown. Here, using a computational approach, we explored whether γ-drive emerges in an artificial neural network model of the corticospinal system linked to a biomechanical antagonist wrist simulator. The wrist simulator included length-sensitive and γ-drive-dependent type Ia and type II muscle spindle activity. Network activity and connectivity were derived by a gradient descent algorithm to generate reciprocal, known target α-motor unit activity during wrist flexion-extension (F/E) movements. Two tasks were simulated: an alternating F/E task and a slow F/E tracking task. Emergence of γ-motor activity in the alternating F/E network was a function of α-motor unit drive: if muscle afferent (together with supraspinal) input was required for driving α-motor units, then γ-drive emerged in the form of α-γ coactivation, as predicted by empirical studies. In the slow F/E tracking network, γ-drive emerged in the form of α-γ dissociation and provided critical, bidirectional muscle afferent activity to the cortical network, containing known bidirectional target units. The model thus demonstrates the complementary aspects of spindle output and hence γ-drive: i) muscle spindle activity as a driving force of α-motor unit activity, and ii) afferent activity providing continuous sensory information, both of which crucially depend on γ-drive.

VAV-1 acts in a single interneuron to inhibit motor circuit activity in Caenorhabditis elegans.

PubMed

Fry, Amanda L; Laboy, Jocelyn T; Norman, Kenneth R

2014-11-21

The complex molecular and cellular mechanisms underlying neuronal control of animal movement are not well understood. Locomotion of Caenorhabditis elegans is mediated by a neuronal circuit that produces coordinated sinusoidal movement. Here we utilize this simple, yet elegant, behaviour to show that VAV-1, a conserved guanine nucleotide exchange factor for Rho-family GTPases, negatively regulates motor circuit activity and the rate of locomotion. While vav-1 is expressed in a small subset of neurons, we find that VAV-1 function is required in a single interneuron, ALA, to regulate motor neuron circuit activity. Furthermore, we show by genetic and optogenetic manipulation of ALA that VAV-1 is required for the excitation and activation of this neuron. We find that ALA signalling inhibits command interneuron activity by abrogating excitatory signalling in the command interneurons, which is responsible for promoting motor neuron circuit activity. Together, our data describe a novel neuromodulatory role for VAV-1-dependent signalling in the regulation of motor circuit activity and locomotion.

Gross Motor Development.

ERIC Educational Resources Information Center

Florida Learning Resources System/CROWN, Jacksonville.

The document is designed to help teachers identify and remediate gross motor development deficits in elementary school students. A definition of gross motor development and a checklist of gross motor skills are provided. Sections cover the following topics: successful teaching techniques; activities for perceptual-motor training; activities for…

Supplementary motor area and primary auditory cortex activation in an expert break-dancer during the kinesthetic motor imagery of dance to music.

PubMed

Olshansky, Michael P; Bar, Rachel J; Fogarty, Mary; DeSouza, Joseph F X

2015-01-01

The current study used functional magnetic resonance imaging to examine the neural activity of an expert dancer with 35 years of break-dancing experience during the kinesthetic motor imagery (KMI) of dance accompanied by highly familiar and unfamiliar music. The goal of this study was to examine the effect of musical familiarity on neural activity underlying KMI within a highly experienced dancer. In order to investigate this in both primary sensory and motor planning cortical areas, we examined the effects of music familiarity on the primary auditory cortex [Heschl's gyrus (HG)] and the supplementary motor area (SMA). Our findings reveal reduced HG activity and greater SMA activity during imagined dance to familiar music compared to unfamiliar music. We propose that one's internal representations of dance moves are influenced by auditory stimuli and may be specific to a dance style and the music accompanying it.

Predictability of action sub-steps modulates motor system activation during the observation of goal-directed actions.

PubMed

Braukmann, Ricarda; Bekkering, Harold; Hidding, Margreeth; Poljac, Edita; Buitelaar, Jan K; Hunnius, Sabine

2017-08-01

Action perception and execution are linked in the human motor system, and researchers have proposed that this action-observation matching system underlies our ability to predict observed behavior. If the motor system is indeed involved in the generation of action predictions, activation should be modulated by the degree of predictability of an observed action. This study used EEG and eye-tracking to investigate whether and how predictability of an observed action modulates motor system activation as well as behavioral predictions in the form of anticipatory eye-movements. Participants were presented with object-directed actions (e.g., making a cup of tea) consisting of three action steps which increased in their predictability. While the goal of the first step was ambiguous (e.g., when making tea, one can first grab the teabag or the cup), the goals of the following steps became predictable over the course of the action. Motor system activation was assessed by measuring attenuation of sensorimotor mu- and beta-oscillations. We found that mu- and beta-power were attenuated during observation, indicating general activation of the motor system. Importantly, predictive motor system activation, indexed by beta-band attenuation, increased for each action step, showing strongest activation prior to the final (i.e. most predictable) step. Sensorimotor activity was related to participants' predictive eye-movements which also showed a modulation by action step. Our results demonstrate that motor system activity and behavioral predictions become stronger for more predictable action steps. The functional roles of sensorimotor oscillations in predicting other's actions are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

The relationship among physical activity, motor competence and health-related fitness in 14-year-old adolescents.

PubMed

Hands, B; Larkin, D; Parker, H; Straker, L; Perry, M

2009-10-01

Physical activity, physical fitness and motor competence are important health-related constructs. However, the relationship among them, particularly for children and adolescents, is still unclear. In this study, motor competence (measured by the McCarron Assessment of Neuromuscular Development), pedometer-determined physical activity and physical fitness (aerobic fitness, muscle strength, muscle endurance, flexibility and body composition) were examined in a cohort of 1585 adolescents (771 girls, 814 boys) of mean age 14.06 years. Significant gender differences were observed for all measures except motor competence. Apart from hip and shoulder flexibility, males outperformed females. For both males and females, motor competence was associated with all fitness measures, physical activity was associated only with aerobic fitness and aerobic fitness was associated with physical activity, motor competence, BMI and chest pass. Among males, aerobic fitness was also associated with all other fitness tests. The correlations were, in general, moderate to weak. The results challenge the current focus on physical activity rather than physical fitness as the preferred intervention.

Auditory-Motor Processing of Speech Sounds

PubMed Central

Möttönen, Riikka; Dutton, Rebekah; Watkins, Kate E.

2013-01-01

The motor regions that control movements of the articulators activate during listening to speech and contribute to performance in demanding speech recognition and discrimination tasks. Whether the articulatory motor cortex modulates auditory processing of speech sounds is unknown. Here, we aimed to determine whether the articulatory motor cortex affects the auditory mechanisms underlying discrimination of speech sounds in the absence of demanding speech tasks. Using electroencephalography, we recorded responses to changes in sound sequences, while participants watched a silent video. We also disrupted the lip or the hand representation in left motor cortex using transcranial magnetic stimulation. Disruption of the lip representation suppressed responses to changes in speech sounds, but not piano tones. In contrast, disruption of the hand representation had no effect on responses to changes in speech sounds. These findings show that disruptions within, but not outside, the articulatory motor cortex impair automatic auditory discrimination of speech sounds. The findings provide evidence for the importance of auditory-motor processes in efficient neural analysis of speech sounds. PMID:22581846

Neurofeedback fMRI-mediated learning and consolidation of regional brain activation during motor imagery

PubMed Central

Yoo, Seung-Schik; Lee, Jong-Hwan; O’Leary, Heather; Panych, Lawrence P.; Jolesz, Ferenc A.

2009-01-01

We report the long-term effect of real-time functional MRI (rtfMRI) training on voluntary regulation of the level of activation from a hand motor area. During the performance of a motor imagery task of a right hand, blood-oxygenation-level-dependent (BOLD) signal originating from a primary motor area was presented back to the subject in real-time. Demographically matched individuals also received the same procedure without valid feedback information. Followed by the initial rtfMRI sessions, both groups underwent two-week long, daily-practice of the task. Off-line data analysis revealed that the individuals in the experimental group were able to increase the level of BOLD signal from the regulatory target to a greater degree compared to the control group. Furthermore, the learned level of activation was maintained after the two-week period, with the recruitment of additional neural circuitries such as the hippocampus and the limbo-thalamo-cortical pathway. The activation obtained from the control group, in the absence of proper feedback, was indifferent across the training conditions. The level of BOLD activity from the target regulatory region was positively correlated with a self evaluative score within the experimental group, while the majority of control subjects had difficulty adopting a strategy to attain the desired level of functional regulation. Our results suggest that rtfMRI helped individuals learn how to increase region-specific cortical activity associated with a motor imagery task, and the level of increased activation in motor areas was consolidated after the two-week self-practice period, with the involvement of neural circuitries implicated in motor skill learning. PMID:19526048

Get Kids Moving: Simple Activities To Build Gross-Motor Skills.

ERIC Educational Resources Information Center

Texas Child Care, 2003

2003-01-01

Highlights the importance of activities to build gross motor skills and provides hints for encouraging such activities. Specific areas of activities presented are: (1) running and jumping; (2) music games; (3) action games; (4) races; (5) bed sheets or parachutes; (6) hula hoops; (7) balls; (8) batting; (9) balance; and (10) creative movement. (SD)

Using Brain Oscillations and Corticospinal Excitability to Understand and Predict Post-Stroke Motor Function

PubMed Central

Thibaut, Aurore; Simis, Marcel; Battistella, Linamara Rizzo; Fanciullacci, Chiara; Bertolucci, Federica; Huerta-Gutierrez, Rodrigo; Chisari, Carmelo; Fregni, Felipe

2017-01-01

What determines motor recovery in stroke is still unknown and finding markers that could predict and improve stroke recovery is a challenge. In this study, we aimed at understanding the neural mechanisms of motor function recovery after stroke using neurophysiological markers by means of cortical excitability (transcranial magnetic stimulation—TMS) and brain oscillations (electroencephalography—EEG). In this cross-sectional study, 55 subjects with chronic stroke (62 ± 14 yo, 17 women, 32 ± 42 months post-stroke) were recruited in two sites. We analyzed TMS measures (i.e., motor threshold—MT—of the affected and unaffected sides) and EEG variables (i.e., power spectrum in different frequency bands and different brain regions of the affected and unaffected hemispheres) and their correlation with motor impairment as measured by Fugl-Meyer. Multiple univariate and multivariate linear regression analyses were performed to identify the predictors of good motor function. A significant interaction effect of MT in the affected hemisphere and power in beta bandwidth over the central region for both affected and unaffected hemispheres was found. We identified that motor function positively correlates with beta rhythm over the central region of the unaffected hemisphere, while it negatively correlates with beta rhythm in the affected hemisphere. Our results suggest that cortical activity in the affected and unaffected hemisphere measured by EEG provides new insights on the association between high-frequency rhythms and motor impairment, highlighting the role of an excess of beta in the affected central cortical region in poor motor function in stroke recovery. PMID:28539912

Using Brain Oscillations and Corticospinal Excitability to Understand and Predict Post-Stroke Motor Function.

PubMed

Thibaut, Aurore; Simis, Marcel; Battistella, Linamara Rizzo; Fanciullacci, Chiara; Bertolucci, Federica; Huerta-Gutierrez, Rodrigo; Chisari, Carmelo; Fregni, Felipe

2017-01-01

What determines motor recovery in stroke is still unknown and finding markers that could predict and improve stroke recovery is a challenge. In this study, we aimed at understanding the neural mechanisms of motor function recovery after stroke using neurophysiological markers by means of cortical excitability (transcranial magnetic stimulation-TMS) and brain oscillations (electroencephalography-EEG). In this cross-sectional study, 55 subjects with chronic stroke (62 ± 14 yo, 17 women, 32 ± 42 months post-stroke) were recruited in two sites. We analyzed TMS measures (i.e., motor threshold-MT-of the affected and unaffected sides) and EEG variables (i.e., power spectrum in different frequency bands and different brain regions of the affected and unaffected hemispheres) and their correlation with motor impairment as measured by Fugl-Meyer. Multiple univariate and multivariate linear regression analyses were performed to identify the predictors of good motor function. A significant interaction effect of MT in the affected hemisphere and power in beta bandwidth over the central region for both affected and unaffected hemispheres was found. We identified that motor function positively correlates with beta rhythm over the central region of the unaffected hemisphere, while it negatively correlates with beta rhythm in the affected hemisphere. Our results suggest that cortical activity in the affected and unaffected hemisphere measured by EEG provides new insights on the association between high-frequency rhythms and motor impairment, highlighting the role of an excess of beta in the affected central cortical region in poor motor function in stroke recovery.

Disassociation between primary motor cortical activity and movement kinematics during adaptation to reach perturbations.

PubMed

Cai, X; Shimansky, Y P; Weber, D J; He, Jiping

2004-01-01

The relationship between movement kinematics and motor cortical activity was studied in monkeys performing a center-out reaching task during their adaptation to force perturbations applied to the wrist. The main feature of adaptive changes in movement kinematics was anticipatory deviation of hand paths in the direction opposite to that of the upcoming perturbation. We identified a group of neurons in the dorsal lateral portion of the primary motor cortex where a gradual buildup of spike activity immediately preceding the actual (in perturbation trials) or the "would-be" (in unperturbed/catch trials) perturbation onset was observed. These neurons were actively involved in the adaptation process, which was evident from the gradual increase in the amplitude of their movement-related modulation of spike activity from virtual zero and development of certain directional tuning pattern (DTP). However, the day-to-day dynamics of the kinematics adaptation was dramatically different from that of the neuronal activity. Hence, the adaptive modification of the motor cortical activity is more likely to reflect the development of the internal model of the perturbation dynamics, rather than motor instructions determining the adaptive behavior.

Ongoing slow oscillatory phase modulates speech intelligibility in cooperation with motor cortical activity.

PubMed

Onojima, Takayuki; Kitajo, Keiichi; Mizuhara, Hiroaki

2017-01-01

Neural oscillation is attracting attention as an underlying mechanism for speech recognition. Speech intelligibility is enhanced by the synchronization of speech rhythms and slow neural oscillation, which is typically observed as human scalp electroencephalography (EEG). In addition to the effect of neural oscillation, it has been proposed that speech recognition is enhanced by the identification of a speaker's motor signals, which are used for speech production. To verify the relationship between the effect of neural oscillation and motor cortical activity, we measured scalp EEG, and simultaneous EEG and functional magnetic resonance imaging (fMRI) during a speech recognition task in which participants were required to recognize spoken words embedded in noise sound. We proposed an index to quantitatively evaluate the EEG phase effect on behavioral performance. The results showed that the delta and theta EEG phase before speech inputs modulated the participant's response time when conducting speech recognition tasks. The simultaneous EEG-fMRI experiment showed that slow EEG activity was correlated with motor cortical activity. These results suggested that the effect of the slow oscillatory phase was associated with the activity of the motor cortex during speech recognition.

Peroxisome proliferator activator receptor gamma coactivator-1alpha (PGC-1α) improves motor performance and survival in a mouse model of amyotrophic lateral sclerosis

PubMed Central

2011-01-01

Background Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that affects spinal cord and cortical motor neurons. An increasing amount of evidence suggests that mitochondrial dysfunction contributes to motor neuron death in ALS. Peroxisome proliferator-activated receptor gamma co-activator-1α (PGC-1α) is a principal regulator of mitochondrial biogenesis and oxidative metabolism. Results In this study, we examined whether PGC-1α plays a protective role in ALS by using a double transgenic mouse model where PGC-1α is over-expressed in an SOD1 transgenic mouse (TgSOD1-G93A/PGC-1α). Our results indicate that PGC-1α significantly improves motor function and survival of SOD1-G93A mice. The behavioral improvements were accompanied by reduced blood glucose level and by protection of motor neuron loss, restoration of mitochondrial electron transport chain activities and inhibition of stress signaling in the spinal cord. Conclusion Our results demonstrate that PGC-1α plays a beneficial role in a mouse model of ALS, suggesting that PGC-1α may be a potential therapeutic target for ALS therapy. PMID:21771318

Weaker Seniors Exhibit Motor Cortex Hypoexcitability and Impairments in Voluntary Activation

PubMed Central

Taylor, Janet L.; Hong, S. Lee; Law, Timothy D.; Russ, David W.

2015-01-01

Background. Weakness predisposes seniors to a fourfold increase in functional limitations. The potential for age-related degradation in nervous system function to contribute to weakness and physical disability has garnered much interest of late. In this study, we tested the hypothesis that weaker seniors have impairments in voluntary (neural) activation and increased indices of GABAergic inhibition of the motor cortex, assessed using transcranial magnetic stimulation. Methods. Young adults (N = 46; 21.2±0.5 years) and seniors (N = 42; 70.7±0.9 years) had their wrist flexion strength quantified along with voluntary activation capacity (by comparing voluntary and electrically evoked forces). Single-pulse transcranial magnetic stimulation was used to measure motor-evoked potential amplitude and silent period duration during isometric contractions at 15% and 30% of maximum strength. Paired-pulse transcranial magnetic stimulation was used to measure intracortical facilitation and short-interval and long-interval intracortical inhibition. The primary analysis compared seniors to young adults. The secondary analysis compared stronger seniors (top two tertiles) to weaker seniors (bottom tertile) based on strength relative to body weight. Results. The most novel findings were that weaker seniors exhibited: (i) a 20% deficit in voluntary activation; (ii) ~20% smaller motor-evoked potentials during the 30% contraction task; and (iii) nearly twofold higher levels of long-interval intracortical inhibition under resting conditions. Conclusions. These findings indicate that weaker seniors exhibit significant impairments in voluntary activation, and that this impairment may be mechanistically associated with increased GABAergic inhibition of the motor cortex. PMID:25834195

3D visualization of movements can amplify motor cortex activation during subsequent motor imagery

PubMed Central

Sollfrank, Teresa; Hart, Daniel; Goodsell, Rachel; Foster, Jonathan; Tan, Tele

2015-01-01

A repetitive movement practice by motor imagery (MI) can influence motor cortical excitability in the electroencephalogram (EEG). This study investigated if a realistic visualization in 3D of upper and lower limb movements can amplify motor related potentials during subsequent MI. We hypothesized that a richer sensory visualization might be more effective during instrumental conditioning, resulting in a more pronounced event related desynchronization (ERD) of the upper alpha band (10–12 Hz) over the sensorimotor cortices thereby potentially improving MI based brain-computer interface (BCI) protocols for motor rehabilitation. The results show a strong increase of the characteristic patterns of ERD of the upper alpha band components for left and right limb MI present over the sensorimotor areas in both visualization conditions. Overall, significant differences were observed as a function of visualization modality (VM; 2D vs. 3D). The largest upper alpha band power decrease was obtained during MI after a 3-dimensional visualization. In total in 12 out of 20 tasks the end-user of the 3D visualization group showed an enhanced upper alpha ERD relative to 2D VM group, with statistical significance in nine tasks.With a realistic visualization of the limb movements, we tried to increase motor cortex activation during subsequent MI. The feedback and the feedback environment should be inherently motivating and relevant for the learner and should have an appeal of novelty, real-world relevance or aesthetic value (Ryan and Deci, 2000; Merrill, 2007). Realistic visual feedback, consistent with the participant’s MI, might be helpful for accomplishing successful MI and the use of such feedback may assist in making BCI a more natural interface for MI based BCI rehabilitation. PMID:26347642

Reduced cortical activation in inferior frontal junction in Unverricht-Lundborg disease (EPM1) - A motor fMRI study.

PubMed

Könönen, Mervi; Danner, Nils; Koskenkorva, Päivi; Kälviäinen, Reetta; Hyppönen, Jelena; Mervaala, Esa; Karjalainen, Pasi; Vanninen, Ritva; Niskanen, Eini

2015-03-01

Unverricht-Lundborg disease (EPM1) is characterized by stimulus-sensitive and action-activated myoclonus, tonic-clonic seizures and ataxia. Several disease-related alterations in cortical structure and excitability have been associated with the motor symptoms of EPM1. This study aimed to elucidate possible alterations in cortical activation related to motor performance in EPM1. Fifteen EPM1-patients and 15 healthy volunteers matched for age and sex underwent motor functional MRI. Group differences in activations were evaluated in the primary and supplementary motor cortices and sensory cortical areas. Furthermore, in EPM1 patients, the quantitative fMRI parameters were correlated with the severity of the motor symptoms. The EPM1-patients exhibited decreased activation in the left inferior frontal junction (IFJ) during right hand voluntary motor task when compared with controls. In the quantitative analysis, EPM1-patients had significantly weaker activation than controls in the hand knob and supplementary motor areas (SMA). The volume of activation in M1 decreased with age and duration of disease in the patient group, whereas the volume increased with age in controls. Negative correlations were observed between fMRI parameters of SMA and disease duration or age in patients but not in controls. The weaker motor fMRI activation observed in EPM1 patients parallels previous neurophysiological findings and correlates with the motor symptoms of the disease. Thus, the observed decrease in IFJ activation in EPM1 patients may be associated with the difficulties in initiation or termination of motor execution, a typical clinical symptom in EPM1. The fMRI findings reflect the progressive nature of this disease. Copyright © 2015 Elsevier B.V. All rights reserved.

Impairments in prehension produced by early postnatal sensory motor cortex activity blockade.

PubMed

Martin, J H; Donarummo, L; Hacking, A

2000-02-01

This study examined the effects of blocking neural activity in sensory motor cortex during early postnatal development on prehension. We infused muscimol, either unilaterally or bilaterally, into the sensory motor cortex of cats to block activity continuously between postnatal weeks 3-7. After stopping infusion, we trained animals to reach and grasp a cube of meat and tested behavior thereafter. Animals that had not received muscimol infusion (unilateral saline infusion; age-matched) reached for the meat accurately with small end-point errors. They grasped the meat using coordinated digit flexion followed by forearm supination on 82.7% of trials. Performance using either limb did not differ significantly. In animals receiving unilateral muscimol infusion, reaching and grasping using the limb ipsilateral to the infusion were similar to controls. The limb contralateral to infusion showed significant increases in systematic and variable reaching end-point errors, often requiring subsequent corrective movements to contact the meat. Grasping occurred on only 14.8% of trials, replaced on most trials by raking without distal movements. Compensatory adjustments in reach length and angle, to maintain end-point accuracy as movements were started from a more lateral position, were less effective using the contralateral limb than ipsilateral limb. With bilateral inactivations, the form of reaching and grasping impairments was identical to that produced by unilateral inactivation, but the magnitude of the reaching impairments was less. We discuss these results in terms of the differential effects of unilateral and bilateral inactivation on corticospinal tract development. We also investigated the degree to which these prehension impairments after unilateral blockade reflect control by each hemisphere. In animals that had received unilateral blockade between postnatal weeks (PWs) 3 and 7, we silenced on-going activity (after PW 11) during task performance using continuous

Effect of light on the activity of motor cortex neurons during locomotion

PubMed Central

Armer, Madison C.; Nilaweera, Wijitha U.; Rivers, Trevor J.; Dasgupta, Namrata M.; Beloozerova, Irina N.

2013-01-01

The motor cortex plays a critical role in accurate visually guided movements such as reaching and target stepping. However, the manner in which vision influences the movement-related activity of neurons in the motor cortex is not well understood. In this study we have investigated how the locomotion-related activity of neurons in the motor cortex is modified when subjects switch between walking in the darkness and in light. Three adult cats were trained to walk through corridors of an experimental chamber for a food reward. On randomly selected trials, lights were extinguished for approximately four seconds when the cat was in a straight portion of the chamber's corridor. Discharges of 146 neurons from layer V of the motor cortex, including 51 pyramidal tract cells (PTNs), were recorded and compared between light and dark conditions. It was found that while cats’ movements during locomotion in light and darkness were similar (as judged from the analysis of three-dimensional limb kinematics and the activity of limb muscles), the firing behavior of 49% (71/146) of neurons was different between the two walking conditions. This included differences in the mean discharge rate (19%, 28/146 of neurons), depth of stride-related frequency modulation (24%, 32/131), duration of the period of elevated firing ([PEF], 19%, 25/131), and number of PEFs among stride-related neurons (26%, 34/131). 20% of responding neurons exhibited more than one type of change. We conclude that visual input plays a very significant role in determining neuronal activity in the motor cortex during locomotion by altering one, or occasionally multiple, parameters of locomotion-related discharges of its neurons. PMID:23680161

Motor co-activation in siblings of patients with juvenile myoclonic epilepsy: an imaging endophenotype?

PubMed Central

Wandschneider, Britta; Centeno, Maria; Vollmar, Christian; Symms, Mark; Thompson, Pamela J.; Duncan, John S.

2014-01-01

Juvenile myoclonic epilepsy is a heritable idiopathic generalized epilepsy syndrome, characterized by myoclonic jerks and frequently triggered by cognitive effort. Impairment of frontal lobe cognitive functions has been reported in patients with juvenile myoclonic epilepsy and their unaffected siblings. In a recent functional magnetic resonance imaging study we reported abnormal co-activation of the motor cortex and increased functional connectivity between the motor system and prefrontal cognitive networks during a working memory paradigm, providing an underlying mechanism for cognitively triggered jerks. In this study, we used the same task in 15 unaffected siblings (10 female; age range 18–65 years, median 40) of 11 of those patients with juvenile myoclonic epilepsy (six female; age range 22–54 years, median 35) and compared functional magnetic resonance imaging activations with 20 age- and gender-matched healthy control subjects (12 female; age range 23–46 years, median 30.5). Unaffected siblings showed abnormal primary motor cortex and supplementary motor area co-activation with increasing cognitive load, as well as increased task-related functional connectivity between motor and prefrontal cognitive networks, with a similar pattern to patients (P < 0.001 uncorrected; 20-voxel threshold extent). This finding in unaffected siblings suggests that altered motor system activation and functional connectivity is not medication- or seizure-related, but represents a potential underlying mechanism for impairment of frontal lobe functions in both patients and siblings, and so constitutes an endophenotype of juvenile myoclonic epilepsy. PMID:25001494

Sport and Other Motor Activities of Warsaw Students

ERIC Educational Resources Information Center

Biernat, Elzbieta

2011-01-01

Study aim: To assess the engagement of students of Warsaw university schools in sports and in recreational motor activities. Material and methods: A cohort (n = 1100) of students attending B.S. or M.S. courses at 6 university schools in Warsaw were studied by applying questionnaire techniques. The questions pertained to participation in…

On the nature of extraversion: variation in conditioned contextual activation of dopamine-facilitated affective, cognitive, and motor processes

PubMed Central

Depue, Richard A.; Fu, Yu

2013-01-01

Research supports an association between extraversion and dopamine (DA) functioning. DA facilitates incentive motivation and the conditioning and incentive encoding of contexts that predict reward. Therefore, we assessed whether extraversion is related to the efficacy of acquiring conditioned contextual facilitation of three processes that are dependent on DA: motor velocity, positive affect, and visuospatial working memory. We exposed high and low extraverts to three days of association of drug reward (methylphenidate, MP) with a particular laboratory context (Paired group), a test day of conditioning, and three days of extinction in the same laboratory. A Placebo group and an Unpaired group (that had MP in a different laboratory context) served as controls. Conditioned contextual facilitation was assessed by (i) presenting video clips that varied in their pairing with drug and laboratory context and in inherent incentive value, and (ii) measuring increases from day 1 to Test day on the three processes above. Results showed acquisition of conditioned contextual facilitation across all measures to video clips that had been paired with drug and laboratory context in the Paired high extraverts, but no conditioning in the Paired low extraverts (nor in either of the control groups). Increases in the Paired high extraverts were correlated across the three measures. Also, conditioned facilitation was evident on the first day of extinction in Paired high extraverts, despite the absence of the unconditioned effects of MP. By the last day of extinction, responding returned to day 1 levels. The findings suggest that extraversion is associated with variation in the acquisition of contexts that predict reward. Over time, this variation may lead to differences in the breadth of networks of conditioned contexts. Thus, individual differences in extraversion may be maintained by activation of differentially encoded central representations of incentive contexts that predict reward

ATF3 expression improves motor function in the ALS mouse model by promoting motor neuron survival and retaining muscle innervation.

PubMed

Seijffers, Rhona; Zhang, Jiangwen; Matthews, Jonathan C; Chen, Adam; Tamrazian, Eric; Babaniyi, Olusegun; Selig, Martin; Hynynen, Meri; Woolf, Clifford J; Brown, Robert H

2014-01-28

ALS is a fatal neurodegenerative disease characterized by a progressive loss of motor neurons and atrophy of distal axon terminals in muscle, resulting in loss of motor function. Motor end plates denervated by axonal retraction of dying motor neurons are partially reinnervated by remaining viable motor neurons; however, this axonal sprouting is insufficient to compensate for motor neuron loss. Activating transcription factor 3 (ATF3) promotes neuronal survival and axonal growth. Here, we reveal that forced expression of ATF3 in motor neurons of transgenic SOD1(G93A) ALS mice delays neuromuscular junction denervation by inducing axonal sprouting and enhancing motor neuron viability. Maintenance of neuromuscular junction innervation during the course of the disease in ATF3/SOD1(G93A) mice is associated with a substantial delay in muscle atrophy and improved motor performance. Although disease onset and mortality are delayed, disease duration is not affected. This study shows that adaptive axonal growth-promoting mechanisms can substantially improve motor function in ALS and importantly, that augmenting viability of the motor neuron soma and maintaining functional neuromuscular junction connections are both essential elements in therapy for motor neuron disease in the SOD1(G93A) mice. Accordingly, effective protection of optimal motor neuron function requires restitution of multiple dysregulated cellular pathways.

Motor (but not auditory) attention affects syntactic choice.

PubMed

Pokhoday, Mikhail; Scheepers, Christoph; Shtyrov, Yury; Myachykov, Andriy

2018-01-01

Understanding the determinants of syntactic choice in sentence production is a salient topic in psycholinguistics. Existing evidence suggests that syntactic choice results from an interplay between linguistic and non-linguistic factors, and a speaker's attention to the elements of a described event represents one such factor. Whereas multimodal accounts of attention suggest a role for different modalities in this process, existing studies examining attention effects in syntactic choice are primarily based on visual cueing paradigms. Hence, it remains unclear whether attentional effects on syntactic choice are limited to the visual modality or are indeed more general. This issue is addressed by the current study. Native English participants viewed and described line drawings of simple transitive events while their attention was directed to the location of the agent or the patient of the depicted event by means of either an auditory (monaural beep) or a motor (unilateral key press) lateral cue. Our results show an effect of cue location, with participants producing more passive-voice descriptions in the patient-cued conditions. Crucially, this cue location effect emerged in the motor-cue but not (or substantially less so) in the auditory-cue condition, as confirmed by a reliable interaction between cue location (agent vs. patient) and cue type (auditory vs. motor). Our data suggest that attentional effects on the speaker's syntactic choices are modality-specific and limited to the visual and motor, but not the auditory, domain.

Poor supplementary motor area activation differentiates auditory verbal hallucination from imagining the hallucination☆

PubMed Central

Raij, Tuukka T.; Riekki, Tapani J.J.

2012-01-01

Neuronal underpinnings of auditory verbal hallucination remain poorly understood. One suggested mechanism is brain activation that is similar to verbal imagery but occurs without the proper activation of the neuronal systems that are required to tag the origins of verbal imagery in one's mind. Such neuronal systems involve the supplementary motor area. The supplementary motor area has been associated with awareness of intention to make a hand movement, but whether this region is related to the sense of ownership of one's verbal thought remains poorly known. We hypothesized that the supplementary motor area is related to the distinction between one's own mental processing (auditory verbal imagery) and similar processing that is attributed to non-self author (auditory verbal hallucination). To test this hypothesis, we asked patients to signal the onset and offset of their auditory verbal hallucinations during functional magnetic resonance imaging. During non-hallucination periods, we asked the same patients to imagine the hallucination they had previously experienced. In addition, healthy control subjects signaled the onset and offset of self-paced imagery of similar voices. Both hallucinations and the imagery of hallucinations were associated with similar activation strengths of the fronto-temporal language-related circuitries, but the supplementary motor area was activated more strongly during the imagery than during hallucination. These findings suggest that auditory verbal hallucination resembles verbal imagery in language processing, but without the involvement of the supplementary motor area, which may subserve the sense of ownership of one's own verbal imagery. PMID:24179739

Neurophysiological substrates of stroke patients with motor imagery-based Brain-Computer Interface training.

PubMed

Li, Mingfen; Liu, Ye; Wu, Yi; Liu, Sirao; Jia, Jie; Zhang, Liqing

2014-06-01

We investigated the efficacy of motor imagery-based Brain Computer Interface (MI-based BCI) training for eight stroke patients with severe upper extremity paralysis using longitudinal clinical assessments. The results were compared with those of a control group (n = 7) that only received FES (Functional Electrical Stimulation) treatment besides conventional therapies. During rehabilitation training, changes in the motor function of the upper extremity and in the neurophysiologic electroencephalographic (EEG) were observed for two groups. After 8 weeks of training, a significant improvement in the motor function of the upper extremity for the BCI group was confirmed (p < 0.05 for ARAT), simultaneously with the activation of bilateral cerebral hemispheres. Additionally, event-related desynchronization (ERD) of the affected sensorimotor cortexes (SMCs) was significantly enhanced when compared to the pretraining course, which was only observed in the BCI group (p < 0.05). Furthermore, the activation of affected SMC and parietal lobe were determined to contribute to motor function recovery (p < 0.05). In brief, our findings demonstrate that MI-based BCI training can enhance the motor function of the upper extremity for stroke patients by inducing the optimal cerebral motor functional reorganization.

Neuron-Glia Crosstalk and Neuropathic Pain: Involvement in the Modulation of Motor Activity in the Orofacial Region.

PubMed

Hossain, Mohammad Zakir; Unno, Shumpei; Ando, Hiroshi; Masuda, Yuji; Kitagawa, Junichi

2017-09-26

Neuropathic orofacial pain (NOP) is a debilitating condition. Although the pathophysiology remains unclear, accumulating evidence suggests the involvement of multiple mechanisms in the development of neuropathic pain. Recently, glial cells have been shown to play a key pathogenetic role. Nerve injury leads to an immune response near the site of injury. Satellite glial cells are activated in the peripheral ganglia. Various neural and immune mediators, released at the central terminals of primary afferents, lead to the sensitization of postsynaptic neurons and the activation of glia. The activated glia, in turn, release pro-inflammatory factors, further sensitizing the neurons, and resulting in central sensitization. Recently, we observed the involvement of glia in the alteration of orofacial motor activity in NOP. Microglia and astroglia were activated in the trigeminal sensory and motor nuclei, in parallel with altered motor functions and a decreased pain threshold. A microglial blocker attenuated the reduction in pain threshold, reduced the number of activated microglia, and restored motor activity. We also found an involvement of the astroglial glutamate-glutamine shuttle in the trigeminal motor nucleus in the alteration of the jaw reflex. Neuron-glia crosstalk thus plays an important role in the development of pain and altered motor activity in NOP.

Neuron–Glia Crosstalk and Neuropathic Pain: Involvement in the Modulation of Motor Activity in the Orofacial Region

PubMed Central

Unno, Shumpei; Ando, Hiroshi; Masuda, Yuji; Kitagawa, Junichi

2017-01-01

Neuropathic orofacial pain (NOP) is a debilitating condition. Although the pathophysiology remains unclear, accumulating evidence suggests the involvement of multiple mechanisms in the development of neuropathic pain. Recently, glial cells have been shown to play a key pathogenetic role. Nerve injury leads to an immune response near the site of injury. Satellite glial cells are activated in the peripheral ganglia. Various neural and immune mediators, released at the central terminals of primary afferents, lead to the sensitization of postsynaptic neurons and the activation of glia. The activated glia, in turn, release pro-inflammatory factors, further sensitizing the neurons, and resulting in central sensitization. Recently, we observed the involvement of glia in the alteration of orofacial motor activity in NOP. Microglia and astroglia were activated in the trigeminal sensory and motor nuclei, in parallel with altered motor functions and a decreased pain threshold. A microglial blocker attenuated the reduction in pain threshold, reduced the number of activated microglia, and restored motor activity. We also found an involvement of the astroglial glutamate–glutamine shuttle in the trigeminal motor nucleus in the alteration of the jaw reflex. Neuron–glia crosstalk thus plays an important role in the development of pain and altered motor activity in NOP. PMID:28954391

D2 receptor genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans.

PubMed

Fazio, Leonardo; Blasi, Giuseppe; Taurisano, Paolo; Papazacharias, Apostolos; Romano, Raffaella; Gelao, Barbara; Ursini, Gianluca; Quarto, Tiziana; Lo Bianco, Luciana; Di Giorgio, Annabella; Mancini, Marina; Popolizio, Teresa; Rubini, Giuseppe; Bertolino, Alessandro

2011-02-14

Pre-synaptic D2 receptors regulate striatal dopamine release and DAT activity, key factors for modulation of motor pathways. A functional SNP of DRD2 (rs1076560 G>T) is associated with alternative splicing such that the relative expression of D2S (mainly pre-synaptic) vs. D2L (mainly post-synaptic) receptor isoforms is decreased in subjects with the T allele with a putative increase of striatal dopamine levels. To evaluate how DRD2 genotype and striatal dopamine signaling predict motor cortical activity and behavior in humans, we have investigated the association of rs1076560 with BOLD fMRI activity during a motor task. To further evaluate the relationship of this circuitry with dopamine signaling, we also explored the correlation between genotype based differences in motor brain activity and pre-synaptic striatal DAT binding measured with [(123)I] FP-CIT SPECT. Fifty healthy subjects, genotyped for DRD2 rs1076560 were studied with BOLD-fMRI at 3T while performing a visually paced motor task with their right hand; eleven of these subjects also underwent [(123)I]FP-CIT SPECT. SPM5 random-effects models were used for statistical analyses. Subjects carrying the T allele had greater BOLD responses in left basal ganglia, thalamus, supplementary motor area, and primary motor cortex, whose activity was also negatively correlated with reaction time at the task. Moreover, left striatal DAT binding and activity of left supplementary motor area were negatively correlated. The present results suggest that DRD2 genetic variation was associated with focusing of responses in the whole motor network, in which activity of predictable nodes was correlated with reaction time and with striatal pre-synaptic dopamine signaling. Our results in humans may help shed light on genetic risk for neurobiological mechanisms involved in the pathophysiology of disorders with dysregulation of striatal dopamine like Parkinson's disease. Copyright © 2010 Elsevier Inc. All rights reserved.

[Effect of the sharply strengthened motor activity on heart pumping ability of rats and mechanisms of its regulation].

PubMed

Nikitin, A S; Abzalov, R A; Abzalov, N I; Vafina, E Z

2013-08-01

The indicators of heart pumping ability of rats at a muscular loading of the maximum power and also in the conditions of transition from sharply strengthened motor activity regime on a strengthened motor activity regime at adrenergic influence stimulation and blockade were investigated. At rats of 100-daily age at the strengthened motor activity heart rate is less, and blood stroke volume is more, than in the rats, subject to muscular loading of the maximum power. The adrenergic influence on the heart's pumping ability of sharply strengthened motor activity rats is much more, than of unlimited motor activity rats. At the α1-adrenoreceptors blockade at 100-daily rats the decreasing in intensity of muscular loading causes increased in adrenergic influence on heart pumping ability.

Does Physical Self-Concept Mediate the Relationship between Motor Abilities and Physical Activity in Adolescents and Young Adults?

PubMed Central

Jekauc, Darko; Wagner, Matthias Oliver; Herrmann, Christian; Hegazy, Khaled; Woll, Alexander

2017-01-01

The purpose of this study is to examine the reciprocal relationship between motor abilities and physical activity and the mediation effects of physical self-concept in this relationship using longitudinal data. We expect that the effects of motor abilities on physical activity are rather indirect via physical self-concept and that the effects of physical activity on motor abilities are rather direct without involvement of the motor ability self-concept. Data was obtained from the Motorik-Modul (MoMo) Longitudinal Study in which 335 boys and 363 girls aged 11–17 years old at Baseline were examined twice in a period of six years. Physical activity was assessed by the MoMo Physical Activity Questionnaire for adolescents, physical self-concept by Physical Self-Description Questionnaire and motor abilities by MoMo Motor Test which comprised of the dimensions strength, endurance, coordination and flexibility. Multiple regression analyses were used to analyse the direct and indirect effects. The results of the multiple regression analyses show that the effects of motor abilities on physical activity were only indirect for the dimensions strength, coordination, and flexibility. For the dimension endurance, neither direct nor indirect effects were significant. In the opposite direction, the effects of physical activity on motor abilities were partially mediated by the self-concept of strength. For the dimensions endurance, coordination and flexibility, only indirect were significant. The results of this study support the assumption that the relationship between motor abilities and physical activity is mediated by physical self-concept in both directions. Physical self-concept seems to be an important determinant of adolescents´ physical activity. PMID:28045914

Does Physical Self-Concept Mediate the Relationship between Motor Abilities and Physical Activity in Adolescents and Young Adults?

PubMed

Jekauc, Darko; Wagner, Matthias Oliver; Herrmann, Christian; Hegazy, Khaled; Woll, Alexander

2017-01-01

The purpose of this study is to examine the reciprocal relationship between motor abilities and physical activity and the mediation effects of physical self-concept in this relationship using longitudinal data. We expect that the effects of motor abilities on physical activity are rather indirect via physical self-concept and that the effects of physical activity on motor abilities are rather direct without involvement of the motor ability self-concept. Data was obtained from the Motorik-Modul (MoMo) Longitudinal Study in which 335 boys and 363 girls aged 11-17 years old at Baseline were examined twice in a period of six years. Physical activity was assessed by the MoMo Physical Activity Questionnaire for adolescents, physical self-concept by Physical Self-Description Questionnaire and motor abilities by MoMo Motor Test which comprised of the dimensions strength, endurance, coordination and flexibility. Multiple regression analyses were used to analyse the direct and indirect effects. The results of the multiple regression analyses show that the effects of motor abilities on physical activity were only indirect for the dimensions strength, coordination, and flexibility. For the dimension endurance, neither direct nor indirect effects were significant. In the opposite direction, the effects of physical activity on motor abilities were partially mediated by the self-concept of strength. For the dimensions endurance, coordination and flexibility, only indirect were significant. The results of this study support the assumption that the relationship between motor abilities and physical activity is mediated by physical self-concept in both directions. Physical self-concept seems to be an important determinant of adolescents´ physical activity.

Comparison of adult physical activity levels in three Swiss alpine communities with varying access to motorized transportation.

PubMed

Dombois, Oliver Thommen; Braun-Fahrländer, Charlotte; Martin-Diener, Eva

2007-09-01

To compare physical activity levels of residents of three Swiss alpine communities with varying access to motorized transport and to investigate whether socio-demographic factors, the settlement structure or means of transport affect these levels. Between January and February 2004 a computer assisted telephone interview was conducted with 901 randomly selected adults aged 18 years or older living in three Swiss alpine communities. In particular, information on moderate and vigorous intensity physical activities and on transport behaviour was collected. Respondents were categorized as 'sufficiently active' or 'insufficiently active' according to self-reported physical activity. People living in community 1 without access to motorized traffic were significantly more likely to be sufficiently active (Sex- and age-adjusted prevalences of sufficient total physical activity, 43.9% 95% CI: 38.3%-49.8%) compared to individuals living in the other two communities (community 2: 35.9%, 95% CI: 30.6%-41.6%, community 3: 32.7%, 95% CI: 27.5%-38.3%). The differences were due to higher levels of moderate physical activities. Vigorous physical activity levels did not differ between the communities. Community differences were explained by passive means of transport to work and for leisure time activities. Although the environment encountered in the three alpine communities is generally conducive to physical activity the majority of the participants did not achieve recommended activity levels. Passive mode of transport to work and during leisure time was strongly associated with insufficient total physical activity. Walking and cycling for transportation is thus a promising approach to promote health enhancing physical activity.

rTMS with Motor Training Modulates Cortico-Basal Ganglia-Thalamocortical Circuits in Stroke Patients

PubMed Central

Chang, Won Hyuk; Kim, Yun-Hee; Yoo, Woo-Kyoung; Goo, Kyoung-Hyup; Park, Chang-hyun; Kim, Sung Tae; Pascual-Leone, Alvaro

2013-01-01

Background and Purpose Repetitive transcranial magnetic stimulation (rTMS) may enhance plastic changes in the human cortex and modulation of behavior. However, the underlying neural mechanisms have not been sufficiently investigated. We examined the clinical effects and neural correlates of high-frequency rTMS coupled with motor training in patients with hemiparesis after stroke. Methods Twenty-one patients were randomly divided into two groups, and received either real or sham rTMS. Ten daily sessions of 1,000 pulses of real or sham rTMS were applied at 10 Hz over the primary motor cortex of the affected hemisphere, coupled with sequential finger motor training of the paretic hand. Functional MRIs were obtained before and after training using sequential finger motor tasks, and performances were assessed. Results Following rTMS intervention, movement accuracy of sequential finger motor tasks showed significantly greater improvement in the real group than in the sham group (p<0.05). Real rTMS modulated areas of brain activation during performance of motor tasks with a significant interaction effect in the sensorimotor cortex, thalamus, and caudate nucleus. Patients in the real rTMS group also showed significantly enhanced activation in the affected hemisphere compared to the sham rTMS group. Conclusion According to these results, a 10 day course of high-frequency rTMS coupled with motor training improved motor performance through modulation of activities in the cortico-basal ganglia-thalamocortical circuits. PMID:22555430

Visual, Motor, and Visual-Motor Integration Difficulties in Students with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Oliver, Kimberly

2013-01-01

Autism spectrum disorders (ASDs) affect 1 in every 88 U.S. children. ASDs have been described as neurological and developmental disorders impacting visual, motor, and visual-motor integration (VMI) abilities that affect academic achievement (CDC, 2010). Forty-five participants (22 ASD and 23 Typically Developing [TD]) 8 to 14 years old completed…

Physical activity and obesity mediate the association between childhood motor function and adolescents’ academic achievement

PubMed Central

Kantomaa, Marko T.; Stamatakis, Emmanuel; Kankaanpää, Anna; Kaakinen, Marika; Rodriguez, Alina; Taanila, Anja; Ahonen, Timo; Järvelin, Marjo-Riitta; Tammelin, Tuija

2013-01-01

The global epidemic of obesity and physical inactivity may have detrimental implications for young people’s cognitive function and academic achievement. This prospective study investigated whether childhood motor function predicts later academic achievement via physical activity, fitness, and obesity. The study sample included 8,061 children from the Northern Finland Birth Cohort 1986, which contains data about parent-reported motor function at age 8 y and self-reported physical activity, predicted cardiorespiratory fitness (cycle ergometer test), obesity (body weight and height), and academic achievement (grades) at age 16 y. Structural equation models with unstandardized (B) and standardized (β) coefficients were used to test whether, and to what extent, physical activity, cardiorespiratory fitness, and obesity at age 16 mediated the association between childhood motor function and adolescents’ academic achievement. Physical activity was associated with a higher grade-point average, and obesity was associated with a lower grade-point average in adolescence. Furthermore, compromised motor function in childhood had a negative indirect effect on adolescents’ academic achievement via physical inactivity (B = –0.023, 95% confidence interval = –0.031, –0.015) and obesity (B = –0.025, 95% confidence interval = –0.039, –0.011), but not via cardiorespiratory fitness. These results suggest that physical activity and obesity may mediate the association between childhood motor function and adolescents’ academic achievement. Compromised motor function in childhood may represent an important factor driving the effects of obesity and physical inactivity on academic underachievement. PMID:23277558

Physical activity and obesity mediate the association between childhood motor function and adolescents' academic achievement.

PubMed

Kantomaa, Marko T; Stamatakis, Emmanuel; Kankaanpää, Anna; Kaakinen, Marika; Rodriguez, Alina; Taanila, Anja; Ahonen, Timo; Järvelin, Marjo-Riitta; Tammelin, Tuija

2013-01-29

The global epidemic of obesity and physical inactivity may have detrimental implications for young people's cognitive function and academic achievement. This prospective study investigated whether childhood motor function predicts later academic achievement via physical activity, fitness, and obesity. The study sample included 8,061 children from the Northern Finland Birth Cohort 1986, which contains data about parent-reported motor function at age 8 y and self-reported physical activity, predicted cardiorespiratory fitness (cycle ergometer test), obesity (body weight and height), and academic achievement (grades) at age 16 y. Structural equation models with unstandardized (B) and standardized (β) coefficients were used to test whether, and to what extent, physical activity, cardiorespiratory fitness, and obesity at age 16 mediated the association between childhood motor function and adolescents' academic achievement. Physical activity was associated with a higher grade-point average, and obesity was associated with a lower grade-point average in adolescence. Furthermore, compromised motor function in childhood had a negative indirect effect on adolescents' academic achievement via physical inactivity (B = -0.023, 95% confidence interval = -0.031, -0.015) and obesity (B = -0.025, 95% confidence interval = -0.039, -0.011), but not via cardiorespiratory fitness. These results suggest that physical activity and obesity may mediate the association between childhood motor function and adolescents' academic achievement. Compromised motor function in childhood may represent an important factor driving the effects of obesity and physical inactivity on academic underachievement.

Neurofeedback training of alpha-band coherence enhances motor performance.

PubMed

Mottaz, Anais; Solcà, Marco; Magnin, Cécile; Corbet, Tiffany; Schnider, Armin; Guggisberg, Adrian G

2015-09-01

Neurofeedback training of motor cortex activations with brain-computer interface systems can enhance recovery in stroke patients. Here we propose a new approach which trains resting-state functional connectivity associated with motor performance instead of activations related to movements. Ten healthy subjects and one stroke patient trained alpha-band coherence between their hand motor area and the rest of the brain using neurofeedback with source functional connectivity analysis and visual feedback. Seven out of ten healthy subjects were able to increase alpha-band coherence between the hand motor cortex and the rest of the brain in a single session. The patient with chronic stroke learned to enhance alpha-band coherence of his affected primary motor cortex in 7 neurofeedback sessions applied over one month. Coherence increased specifically in the targeted motor cortex and in alpha frequencies. This increase was associated with clinically meaningful and lasting improvement of motor function after stroke. These results provide proof of concept that neurofeedback training of alpha-band coherence is feasible and behaviorally useful. The study presents evidence for a role of alpha-band coherence in motor learning and may lead to new strategies for rehabilitation. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Mathematical modeling of alignment dynamics in active motor-filament systems

NASA Astrophysics Data System (ADS)

Swaminathan, Sumanth

The formation of the cytoskeleton, via motor-mediated microtubule self-organization, is an important subject of study in the biological sciences as well as in nonequilibrium, soft matter physics. Accurate modeling of the dynamics is a formidable task as it involves intrinsic nonlinearities, structural anisotropies, nonequilibrium processes, and a broad window of time scales, length scales, and densities. In this thesis, we study the ordering dynamics and pattern formations arising from motor-mediated microtubule self-organization in dilute and semi-dilute filament solutions. In the dilute case, we use a probabilistic model in which microtubules interact through motor induced, inelastic binary collisions. This model shows that initially disordered filament solutions exhibit an ordering transition resulting in the emergence of well aligned rod bundles. We study the existence and dynamic interaction of microtubule bundles analytically and numerically. Our results show a long term attraction and coalescing of bundles indicating a clear coarsening in the system; microtubule bundles concentrate into fewer orientations on a slow logarithmic time scale. In the semi-dilute case, multiple motors can bind a filament to several others and, for a critical motor density, induce a transition to an ordered state with a nonzero mean orientation. We develop a spatially homogeneous, mean-field theory that explicitly accounts for motor forcing and thermal fluctuations which enter into the model as multiplicative and additive noises respectively. Our model further incorporates a force-dependent detachment rate of motors, which in turn affects the mean and the fluctuations of the net force acting on a filament. We demonstrate that the transition to the oriented state changes from second order to first order when the force-dependent detachment becomes important. In our final analysis, we add complex spatial inhomogeneities to our mean field theory. The revised model consists of a system

Brain Activation in Motor Sequence Learning Is Related to the Level of Native Cortical Excitability

PubMed Central

Lissek, Silke; Vallana, Guido S.; Güntürkün, Onur; Dinse, Hubert; Tegenthoff, Martin

2013-01-01

Cortical excitability may be subject to changes through training and learning. Motor training can increase cortical excitability in motor cortex, and facilitation of motor cortical excitability has been shown to be positively correlated with improvements in performance in simple motor tasks. Thus cortical excitability may tentatively be considered as a marker of learning and use-dependent plasticity. Previous studies focused on changes in cortical excitability brought about by learning processes, however, the relation between native levels of cortical excitability on the one hand and brain activation and behavioral parameters on the other is as yet unknown. In the present study we investigated the role of differential native motor cortical excitability for learning a motor sequencing task with regard to post-training changes in excitability, behavioral performance and involvement of brain regions. Our motor task required our participants to reproduce and improvise over a pre-learned motor sequence. Over both task conditions, participants with low cortical excitability (CElo) showed significantly higher BOLD activation in task-relevant brain regions than participants with high cortical excitability (CEhi). In contrast, CElo and CEhi groups did not exhibit differences in percentage of correct responses and improvisation level. Moreover, cortical excitability did not change significantly after learning and training in either group, with the exception of a significant decrease in facilitatory excitability in the CEhi group. The present data suggest that the native, unmanipulated level of cortical excitability is related to brain activation intensity, but not to performance quality. The higher BOLD mean signal intensity during the motor task might reflect a compensatory mechanism in CElo participants. PMID:23613956

Effects of Physical Activity on Motor Skills and Cognitive Development in Early Childhood: A Systematic Review.

PubMed

Zeng, Nan; Ayyub, Mohammad; Sun, Haichun; Wen, Xu; Xiang, Ping; Gao, Zan

2017-01-01

This study synthesized literature concerning casual evidence of effects of various physical activity programs on motor skills and cognitive development in typically developed preschool children. Electronic databases were searched through July 2017. Peer-reviewed randomized controlled trials (RCTs) examining the effectiveness of physical activity on motor skills and cognitive development in healthy young children (4-6 years) were screened. A total of 15 RCTs were included. Of the 10 studies assessing the effects of physical activity on motor skills, eight (80%) reported significant improvements in motor performance and one observed mixed findings, but one failed to promote any beneficial outcomes. Of the five studies investigating the influence of physical activity on cognitive development, four (80%) showed significant and positive changes in language learning, academic achievement, attention, and working memory. Notably, one indicated no significant improvements were observed after the intervention. Findings support causal evidence of effects of physical activity on both motor skills and cognitive development in preschool children. Given the shortage of available studies, future research with large representative samples is warranted to explore the relationships between physical activity and cognitive domains as well as strengthen and confirm the dose-response evidence in early childhood.

Altered gravity affects ventral root activity during fictive swimming and the static vestibuloocular reflex in young tadpoles (Xenopus laevis).

PubMed

Böser, S; Dournon, C; Gualandris-Parisot, L; Horn, E

2008-03-01

During early periods of life, modifications of the gravitational environment affect the development of sensory, neuronal and motor systems. The vestibular system exerts significant effects on motor networks that control eye and body posture as well as swimming. The objective of the present study was to study whether altered gravity (AG) affects vestibuloocular and spinal motor systems in a correlated manner. During the French Soyuz taxi flight Andromède to the International Space Station ISS (launch: October 21, 2001; landing: October 31, 2001) Xenopus laevis embryos were exposed for 10 days to microgravity (microg). In addition, a similar experiment with 3g-hypergravity (3g) was performed in the laboratory. At onset of AG, embryos had reached developmental stages 24 to 27. After exposure to AG, each tadpole was tested for its roll-induced vestibuloocular reflex (rVOR) and 3 hours later it was tested for the neuronal activity recorded from the ventral roots (VR) during fictive swimming. During the post-AG recording periods tadpoles had reached developmental stages 45 to 47. It was observed that microgravity affected VR activity during fictive swimming and rVOR. In particular, VR activity changes included a significant decrease of the rostrocaudal delay and a significant increase of episode duration. The rVOR-amplitude was transiently depressed. Hypergravity was less effective on the locomotor pattern; occurring effects on fictive swimming were the opposite of microg effects. As after microgravity, the rVOR was depressed after 3g-exposure. All modifications of the rVOR and VR-activity recovered to normal levels within 4 to 7 days after termination of AG. Significant correlations between the rVOR amplitude and VR activity of respective tadpoles during the recording period have been observed in both tadpoles with or without AG experience. The data are consistent with the assumptions that during this period of life which is characterized by a progressive development

Enhanced brain motor activity in patients with MS after a single dose of 3,4-diaminopyridine.

PubMed

Mainero, C; Inghilleri, M; Pantano, P; Conte, A; Lenzi, D; Frasca, V; Bozzao, L; Pozzilli, C

2004-06-08

3,4-diaminopyridine (3,4-DAP), a potassium (K+) channel blocker, improves fatigue and motor function in multiple sclerosis (MS). Although it was thought to do so by restoring conduction to demyelinated axons, recent experimental data show that aminopyridines administered at clinical doses potentiate synaptic transmission. To investigate motor cerebral activity with fMRI and transcranial magnetic stimulation (TMS) after a single oral dose of 3,4-DAP in patients with MS. Twelve right-handed women (mean +/- SD age 40.9 +/- 9.3 years) underwent fMRI on two separate occasions (under 3,4-DAP and under placebo) during a simple motor task with the right hand. FMRI data were analyzed with SPM99. After fMRI, patients underwent single-pulse TMS to test motor threshold, amplitude, and latency of motor evoked potentials, central conduction time, and the cortical silent period; paired-pulse TMS to investigate intracortical inhibition (ICI) and intracortical facilitation (ICF); and quantitative electromyography during maximal voluntary contraction. FMRI motor-evoked brain activation was greater under 3,4-DAP than under placebo in the ipsilateral sensorimotor cortex and supplementary motor area (p < 0.05). 3,4-DAP decreased ICI and increased ICF; central motor conduction time and muscular fatigability did not change. 3,4-DAP may modulate brain motor activity in patients with MS, probably by enhancing excitatory synaptic transmission.

Altered impulse activity modifies synaptic physiology and mitochondria in crayfish phasic motor neurons.

PubMed

Nguyen, P V; Atwood, H L

1994-12-01

1. Crayfish phasic motor synapses produce large initial excitatory postsynaptic potentials (EPSPs) that fatigue rapidly during high-frequency stimulation. Periodic in vivo stimulation of an identified phasic abdominal extensor motor neuron (axon 3) induced long-term adaptation (LTA) of neuromuscular transmission: initial EPSP amplitude became smaller and synaptic depression was significantly reduced. We tested the hypothesis that activity-induced synaptic fatigue-resistance seen during LTA was dependent upon, or correlated with, mitochondrial oxidative competence. 2. Periodic unilateral conditioning stimulation of axon 3 entering each of two adjacent homologous abdominal segments (segments 2 and 3) increased the synaptic stamina in both "conditioned" axons; mean final EPSP amplitudes, recorded after 20 min of 5-Hz test stimulation, were significantly larger than those measured with the same protocol from contralateral unstimulated axons. 3. During 5-Hz test stimulation of the conditioned axon 3 of segment 3, acute superfusion with 0.8 mM dinitrophenol or 20 mM sodium azide [inhibitors of oxidative adenosinetriphosphate (ATP) synthesis] produced increased synaptic depression. Drug-free saline superfusion of the conditioned axon 3 of segment 2 in these same animals did not affect the increased synaptic fatigue resistance seen in this segment. Thus both successful induction (in axon 3 of saline-perfused segment 2) and attenuation (in axon 3 of drug-perfused segment 3) of the increased synaptic stamina can be demonstrated with this twin-segment conditioning protocol. 4. Confocal microscopic imaging of mitochondrial rhodamine-123 (Rh123) fluorescence was used to assess relative oxidative competence of conditioned and unconditioned phasic axons. Conditioned phasic axons showed significantly higher mean mitochondrial Rh123 fluorescence than contralateral unstimulated axons. In the same preparations that showed increased postconditioning Rh123 fluorescence, the synaptic

Definition and classification of negative motor signs in childhood.

PubMed

Sanger, Terence D; Chen, Daofen; Delgado, Mauricio R; Gaebler-Spira, Deborah; Hallett, Mark; Mink, Jonathan W

2006-11-01

In this report we describe the outcome of a consensus meeting that occurred at the National Institutes of Health in Bethesda, Maryland, March 12 through 14, 2005. The meeting brought together 39 specialists from multiple clinical and research disciplines including developmental pediatrics, neurology, neurosurgery, orthopedic surgery, physical therapy, occupational therapy, physical medicine and rehabilitation, neurophysiology, muscle physiology, motor control, and biomechanics. The purpose of the meeting was to establish terminology and definitions for 4 aspects of motor disorders that occur in children: weakness, reduced selective motor control, ataxia, and deficits of praxis. The purpose of the definitions is to assist communication between clinicians, select homogeneous groups of children for clinical research trials, facilitate the development of rating scales to assess improvement or deterioration with time, and eventually to better match individual children with specific therapies. "Weakness" is defined as the inability to generate normal voluntary force in a muscle or normal voluntary torque about a joint. "Reduced selective motor control" is defined as the impaired ability to isolate the activation of muscles in a selected pattern in response to demands of a voluntary posture or movement. "Ataxia" is defined as an inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints. "Apraxia" is defined as an impairment in the ability to accomplish previously learned and performed complex motor actions that is not explained by ataxia, reduced selective motor control, weakness, or involuntary motor activity. "Developmental dyspraxia" is defined as a failure to have ever acquired the ability to perform age-appropriate complex motor actions that is not explained by the presence of inadequate demonstration or practice, ataxia, reduced selective motor control

Weaker Seniors Exhibit Motor Cortex Hypoexcitability and Impairments in Voluntary Activation.

PubMed

Clark, Brian C; Taylor, Janet L; Hong, S Lee; Law, Timothy D; Russ, David W

2015-09-01

Weakness predisposes seniors to a fourfold increase in functional limitations. The potential for age-related degradation in nervous system function to contribute to weakness and physical disability has garnered much interest of late. In this study, we tested the hypothesis that weaker seniors have impairments in voluntary (neural) activation and increased indices of GABAergic inhibition of the motor cortex, assessed using transcranial magnetic stimulation. Young adults (N = 46; 21.2±0.5 years) and seniors (N = 42; 70.7±0.9 years) had their wrist flexion strength quantified along with voluntary activation capacity (by comparing voluntary and electrically evoked forces). Single-pulse transcranial magnetic stimulation was used to measure motor-evoked potential amplitude and silent period duration during isometric contractions at 15% and 30% of maximum strength. Paired-pulse transcranial magnetic stimulation was used to measure intracortical facilitation and short-interval and long-interval intracortical inhibition. The primary analysis compared seniors to young adults. The secondary analysis compared stronger seniors (top two tertiles) to weaker seniors (bottom tertile) based on strength relative to body weight. The most novel findings were that weaker seniors exhibited: (i) a 20% deficit in voluntary activation; (ii) ~20% smaller motor-evoked potentials during the 30% contraction task; and (iii) nearly twofold higher levels of long-interval intracortical inhibition under resting conditions. These findings indicate that weaker seniors exhibit significant impairments in voluntary activation, and that this impairment may be mechanistically associated with increased GABAergic inhibition of the motor cortex. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Motor-symptom laterality affects acquisition in Parkinson's disease: A cognitive and functional magnetic resonance imaging study.

PubMed

Huang, Pei; Tan, Yu-Yan; Liu, Dong-Qiang; Herzallah, Mohammad M; Lapidow, Elizabeth; Wang, Ying; Zang, Yu-Feng; Gluck, Mark A; Chen, Sheng-Di

2017-07-01

Asymmetric onset of motor symptoms in PD can affect cognitive function. We examined whether motor-symptom laterality could affect feedback-based associative learning and explored its underlying neural mechanism by functional magnetic resonance imaging in PD patients. We recruited 63 early-stage medication-naïve PD patients (29 left-onset medication-naïve patients, 34 right-onset medication-naïve patients) and 38 matched normal controls. Subjects completed an acquired equivalence task (including acquisition, retention, and generalization) and resting-state functional magnetic resonance imaging scans. Learning accuracy and response time in each phase of the task were recorded for behavioral measures. Regional homogeneity was used to analyze resting-state functional magnetic resonance imaging data, with regional homogeneity lateralization to evaluate hemispheric functional asymmetry in the striatum. Left-onset patients made significantly more errors in acquisition (feedback-based associative learning) than right-onset patients and normal controls, whereas right-onset patients performed as well as normal controls. There was no significant difference among these three groups in the accuracy of either retention or generalization phase. The three groups did not show significant differences in response time. In the left-onset group, there was an inverse relationship between acquisition errors and regional homogeneity in the right dorsal rostral putamen. There were no significant regional homogeneity changes in either the left or the right dorsal rostral putamen in right-onset patients when compared to controls. Motor-symptom laterality could affect feedback-based associative learning in PD, with left-onset medication-naïve patients being selectively impaired. Dysfunction in the right dorsal rostral putamen may underlie the observed deficit in associative learning in patients with left-sided onset.© 2016 International Parkinson and Movement Disorder Society. © 2017

Treatment of the motor and non-motor symptoms in Parkinson's disease according to cluster symptoms presentation.

PubMed

Lauretani, Fulvio; Saginario, Antonio; Ceda, Gian Paolo; Galuppo, Laura; Ruffini, Livia; Nardelli, Anna; Maggio, Marcello

2014-01-01

The term Parkinson's disease has been changed in 'Parkinson's diseases' to describe different clinical entities observed in several studies investigating the existence of PD subtypes. PD patients could be grouped based on clinical features. By considering only motor symptoms, we can classically distinguish two groups: " the tremorigen-form" and "akinetic- rigidity-form" where resting tremor and akinesia/bradikynesia and rigidity are the most motor predominant symptoms, respectively. Non-motor symptoms (NMSs) are practically always present during the course of the disease and some of them (constipation, depressive status, hyposmia and anxiety) could even exist before the onset of classical motor symptoms. Many other NMSs and in particular hallucinations, cognitive impairment, sleep disorders and difficulty in swallowing strongly affect the advanced stage of disease, and represent a real therapeutic challenge when these symptoms are simultaneously present with different severity. If not adequately treated, they can increase the risk of hospitalization and admissions in nursing home, and profoundly and negatively influence the quality of life and participation in social activity of these patients. PD subtypes according to the combination of motor and non-motor symptoms have been recently proposed. This classification derives from cluster analysis which permits to identify statistically distinct subtypes of Parkinsonian patients according to the relevance of both motor and non-motor symptoms. In this point of view, we propose a schematic therapeutic approach of motor and non-motor symptoms in Parkinson's disease according to cluster symptoms presentation (motor and non-motor symptoms) and using medications that act on multiple domains of PD symptoms.

Differential effect of central command on aortic and carotid sinus baroreceptor-heart rate reflexes at the onset of spontaneous, fictive motor activity.

PubMed

Matsukawa, Kanji; Ishii, Kei; Kadowaki, Akito; Liang, Nan; Ishida, Tomoko

2012-08-15

Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in conscious cats and spontaneous contraction in decerebrate cats. The purpose of this study was to examine whether central command attenuates the sensitivity of the carotid sinus baroreceptor-HR reflex at the onset of spontaneous, fictive motor activity in paralyzed, decerebrate cats. We confirmed that aortic nerve (AN)-stimulation-induced bradycardia was markedly blunted to 26 ± 4.4% of the control (21 ± 1.3 beats/min) at the onset of spontaneous motor activity. Although the baroreflex bradycardia by electrical stimulation of the carotid sinus nerve (CSN) was suppressed (P < 0.05) to 86 ± 5.6% of the control (38 ± 1.2 beats/min), the inhibitory effect of spontaneous motor activity was much weaker (P < 0.05) with CSN stimulation than with AN stimulation. The baroreflex bradycardia elicited by brief occlusion of the abdominal aorta was blunted to 36% of the control (36 ± 1.6 beats/min) during spontaneous motor activity, suggesting that central command is able to inhibit the cardiomotor sensitivity of arterial baroreflexes as the net effect. Mechanical stretch of the triceps surae muscle never affected the baroreflex bradycardia elicited by AN or CSN stimulation and by aortic occlusion, suggesting that muscle mechanoreflex did not modify the cardiomotor sensitivity of aortic and carotid sinus baroreflex. Since the inhibitory effect of central command on the carotid baroreflex pathway, associated with spontaneous motor activity, was much weaker compared with the aortic baroreflex pathway, it is concluded that central command does not force a generalized modulation on the whole pathways of arterial baroreflexes but provides selective inhibition for the cardiomotor component of the aortic baroreflex.

Dopamine D1 receptor activation maintains motor coordination in injured rats but does not accelerate the recovery of the motor coordination deficit.

PubMed

Avila-Luna, Alberto; Gálvez-Rosas, Arturo; Alfaro-Rodríguez, Alfonso; Reyes-Legorreta, Celia; Garza-Montaño, Paloma; González-Piña, Rigoberto; Bueno-Nava, Antonio

2018-01-15

The sensorimotor cortex and the striatum are interconnected by the corticostriatal pathway, suggesting that cortical injury alters the striatal function that is associated with skilled movements and motor learning, which are functions that may be modulated by dopamine (DA). In this study, we explored motor coordination and balance in order to investigate whether the activation of D 1 receptors (D 1 Rs) modulates functional recovery after cortical injury. The results of the beam-walking test showed motor deficit in the injured group at 24, 48 and 96h post-injury, and the recovery time was observed at 192h after cortical injury. In the sham and injured rats, systemic administration of the D 1 R antagonist SCH-23390 (1mg/kg) alone at 24, 48, 96 and 192h significantly (P<0.01) increased the motor deficit, while administration of the D 1 R agonist SKF-38393 alone (2, 3 and 4mg/kg) at 24, 48, 96 and 192h post-injury did not produce a significant difference; however, the co-administration of SKF-38393 and SCH-23390 prevented the antagonist-induced increase in the motor deficit. The cortical+striatal injury showed significantly increased the motor deficit at 24, 48, 96 and 192h post-injury (P<0.01) but did not show recovery at 192h. In conclusion, the administration of the D 1 R agonist did not accelerate the motor recovery, but the activation of D 1 Rs maintained motor coordination, confirming that an intact striatum may be necessary for achieving recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of light on the activity of motor cortex neurons during locomotion.

PubMed

Armer, Madison C; Nilaweera, Wijitha U; Rivers, Trevor J; Dasgupta, Namrata M; Beloozerova, Irina N

2013-08-01

The motor cortex plays a critical role in accurate visually guided movements such as reaching and target stepping. However, the manner in which vision influences the movement-related activity of neurons in the motor cortex is not well understood. In this study we have investigated how the locomotion-related activity of neurons in the motor cortex is modified when subjects switch between walking in the darkness and in light. Three adult cats were trained to walk through corridors of an experimental chamber for a food reward. On randomly selected trials, lights were extinguished for approximately 4s when the cat was in a straight portion of the chamber's corridor. Discharges of 146 neurons from layer V of the motor cortex, including 51 pyramidal tract cells (PTNs), were recorded and compared between light and dark conditions. It was found that while cats' movements during locomotion in light and darkness were similar (as judged from the analysis of three-dimensional limb kinematics and the activity of limb muscles), the firing behavior of 49% (71/146) of neurons was different between the two walking conditions. This included differences in the mean discharge rate (19%, 28/146 of neurons), depth of stride-related frequency modulation (24%, 32/131), duration of the period of elevated firing ([PEF], 19%, 25/131), and number of PEFs among stride-related neurons (26%, 34/131). 20% of responding neurons exhibited more than one type of change. We conclude that visual input plays a very significant role in determining neuronal activity in the motor cortex during locomotion by altering one, or occasionally multiple, parameters of locomotion-related discharges of its neurons. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Assessing the feasibility of time-resolved fNIRS to detect brain activity during motor imagery

NASA Astrophysics Data System (ADS)

Abdalmalak, Androu; Milej, Daniel; Diop, Mamadou; Naci, Lorina; Owen, Adrian M.; St. Lawrence, Keith

2016-03-01

Functional near-infrared spectroscopy (fNIRS) is a non-invasive optical technique for detecting brain activity, which has been previously used during motor and motor executive tasks. There is an increasing interest in using fNIRS as a brain computer interface (BCI) for patients who lack the physical, but not the mental, ability to respond to commands. The goal of this study is to assess the feasibility of time-resolved fNIRS to detect brain activity during motor imagery. Stability tests were conducted to ensure the temporal stability of the signal, and motor imagery data were acquired on healthy subjects. The NIRS probes were placed on the scalp over the premotor cortex (PMC) and supplementary motor area (SMA), as these areas are responsible for motion planning. To confirm the fNIRS results, subjects underwent functional magnetic resonance imaging (fMRI) while performing the same task. Seven subjects have participated to date, and significant activation in the SMA and/or the PMC during motor imagery was detected by both fMRI and fNIRS in 4 of the 7 subjects. No activation was detected by either technique in the remaining three participants, which was not unexpected due to the nature of the task. The agreement between the two imaging modalities highlights the potential of fNIRS as a BCI, which could be adapted for bedside studies of patients with disorders of consciousness.

The Dynamic Association between Motor Skill Development and Physical Activity

ERIC Educational Resources Information Center

Stodden, David F.; Goodway, Jacqueline D.

2007-01-01

Although significant attention has been given to promoting physical activity among children, little attention has been given to the developmental process of how children learn to move or to the changing role that motor skill development plays in children's physical activity levels as they grow. In order to successfully address the obesity…

Recreational Activities and Motor Skills of Children in Kindergarten

ERIC Educational Resources Information Center

Temple, Viviene A.; Crane, Jeff R.; Brown, Amy; Williams, Buffy-Lynne; Bell, Rick I.

2016-01-01

Background: Developmental theorists suggest that physical activity during early childhood promotes fundamental motor skill (FMS) proficiency; and that differences in FMS proficiency are largely related to children's experiences. Aim: To examine associations between participation in different types of recreation/leisure and FMS proficiency of boys…

Reconstitution reveals motor activation for intraflagellar transport.

PubMed

Mohamed, Mohamed A A; Stepp, Willi L; Ökten, Zeynep

2018-05-01

The human body represents a notable example of ciliary diversification. Extending from the surface of most cells, cilia accomplish a diverse set of tasks. Predictably, mutations in ciliary genes cause a wide range of human diseases such as male infertility and blindness. In Caenorhabditis elegans sensory cilia, this functional diversity appears to be traceable to the differential regulation of the kinesin-2-powered intraflagellar-transport (IFT) machinery. Here we reconstituted the first, to our knowledge, functional multi-component IFT complex that is deployed in the sensory cilia of C. elegans. Our bottom-up approach revealed the molecular basis of specific motor recruitment to the IFT trains. We identified the key component that incorporates homodimeric kinesin-2 into its physiologically relevant context, which in turn allosterically activates the motor for efficient transport. These results will enable the molecular delineation of IFT regulation, which has eluded understanding since its discovery more than two decades ago.

Eye Gaze Correlates of Motor Impairment in VR Observation of Motor Actions.

PubMed

Alves, J; Vourvopoulos, A; Bernardino, A; Bermúdez I Badia, S

2016-01-01

This article is part of the Focus Theme of Methods of Information in Medicine on "Methodologies, Models and Algorithms for Patients Rehabilitation". Identify eye gaze correlates of motor impairment in a virtual reality motor observation task in a study with healthy participants and stroke patients. Participants consisted of a group of healthy subjects (N = 20) and a group of stroke survivors (N = 10). Both groups were required to observe a simple reach-and-grab and place-and-release task in a virtual environment. Additionally, healthy subjects were required to observe the task in a normal condition and a constrained movement condition. Eye movements were recorded during the observation task for later analysis. For healthy participants, results showed differences in gaze metrics when comparing the normal and arm-constrained conditions. Differences in gaze metrics were also found when comparing dominant and non-dominant arm for saccades and smooth pursuit events. For stroke patients, results showed longer smooth pursuit segments in action observation when observing the paretic arm, thus providing evidence that the affected circuitry may be activated for eye gaze control during observation of the simulated motor action. This study suggests that neural motor circuits are involved, at multiple levels, in observation of motor actions displayed in a virtual reality environment. Thus, eye tracking combined with action observation tasks in a virtual reality display can be used to monitor motor deficits derived from stroke, and consequently can also be used for rehabilitation of stroke patients.

Active Fault Tolerant Control for Ultrasonic Piezoelectric Motor

NASA Astrophysics Data System (ADS)

Boukhnifer, Moussa

2012-07-01

Ultrasonic piezoelectric motor technology is an important system component in integrated mechatronics devices working on extreme operating conditions. Due to these constraints, robustness and performance of the control interfaces should be taken into account in the motor design. In this paper, we apply a new architecture for a fault tolerant control using Youla parameterization for an ultrasonic piezoelectric motor. The distinguished feature of proposed controller architecture is that it shows structurally how the controller design for performance and robustness may be done separately which has the potential to overcome the conflict between performance and robustness in the traditional feedback framework. A fault tolerant control architecture includes two parts: one part for performance and the other part for robustness. The controller design works in such a way that the feedback control system will be solely controlled by the proportional plus double-integral PI2 performance controller for a nominal model without disturbances and H∞ robustification controller will only be activated in the presence of the uncertainties or an external disturbances. The simulation results demonstrate the effectiveness of the proposed fault tolerant control architecture.

Early motor skill competence as a mediator of child and adult physical activity

PubMed Central

Loprinzi, Paul D.; Davis, Robert E.; Fu, Yang-Chieh

2015-01-01

Objective: In order to effectively promote physical activity (PA) during childhood, and across the lifespan, a better understanding of the role of early motor skill development on child and adult PA is needed. Methods: Here, we propose a conceptual model delineating the hypothesized influence of motor skill development on child and adult PA, while providing an overview of the current empirical research related to this model. Results: There is consistent and emerging evidence showing that adequate motor skill competence, particularly locomotor and gross motor skills, is associated with increased PA levels during the preschool, child, and adolescent years, with early motor skill development also influencing enjoyment of PA as well as long-term PA and motor skill performance. The physical education setting appears to be a well-suited environment for motor skill development. Conclusion: Employing appropriate strategies to target motor skill development across the childhood years is of paramount interest in helping shape children's PA behavior, their experiences related to PA, as well as maintain their PA. PMID:26844157

Dominance of the Unaffected Hemisphere Motor Network and Its Role in the Behavior of Chronic Stroke Survivors

PubMed Central

Bajaj, Sahil; Housley, Stephen N.; Wu, David; Dhamala, Mukesh; James, G. A.; Butler, Andrew J.

2016-01-01

Balance of motor network activity between the two brain hemispheres after stroke is crucial for functional recovery. Several studies have extensively studied the role of the affected brain hemisphere to better understand changes in motor network activity following stroke. Very few studies have examined the role of the unaffected brain hemisphere and confirmed the test–retest reliability of connectivity measures on unaffected hemisphere. We recorded blood oxygenation level dependent functional magnetic resonance imaging (fMRI) signals from nine stroke survivors with hemiparesis of the left or right hand. Participants performed a motor execution task with affected hand, unaffected hand, and both hands simultaneously. Participants returned for a repeat fMRI scan 1 week later. Using dynamic causal modeling (DCM), we evaluated effective connectivity among three motor areas: the primary motor area (M1), the premotor cortex (PMC) and the supplementary motor area for the affected and unaffected hemispheres separately. Five participants’ manual motor ability was assessed by Fugl-Meyer Motor Assessment scores and root-mean square error of participants’ tracking ability during a robot-assisted game. We found (i) that the task performance with the affected hand resulted in strengthening of the connectivity pattern for unaffected hemisphere, (ii) an identical network of the unaffected hemisphere when participants performed the task with their unaffected hand, and (iii) the pattern of directional connectivity observed in the affected hemisphere was identical for tasks using the affected hand only or both hands. Furthermore, paired t-test comparison found no significant differences in connectivity strength for any path when compared with one-week follow-up. Brain-behavior linear correlation analysis showed that the connectivity patterns in the unaffected hemisphere more accurately reflected the behavioral conditions than the connectivity patterns in the affected hemisphere

Reduced Activity of AMP-Activated Protein Kinase Protects against Genetic Models of Motor Neuron Disease

PubMed Central

Lim, M. A.; Selak, M. A.; Xiang, Z.; Krainc, D.; Neve, R. L.; Kraemer, B. C.; Watts, J. L.

2012-01-01

A growing body of research indicates that amyotrophic lateral sclerosis (ALS) patients and mouse models of ALS exhibit metabolic dysfunction. A subpopulation of ALS patients possesses higher levels of resting energy expenditure and lower fat-free mass compared to healthy controls. Similarly, two mutant copper zinc superoxide dismutase 1 (mSOD1) mouse models of familial ALS possess a hypermetabolic phenotype. The pathophysiological relevance of the bioenergetic defects observed in ALS remains largely elusive. AMP-activated protein kinase (AMPK) is a key sensor of cellular energy status and thus might be activated in various models of ALS. Here, we report that AMPK activity is increased in spinal cord cultures expressing mSOD1, as well as in spinal cord lysates from mSOD1 mice. Reducing AMPK activity either pharmacologically or genetically prevents mSOD1-induced motor neuron death in vitro. To investigate the role of AMPK in vivo, we used Caenorhabditis elegans models of motor neuron disease. C. elegans engineered to express human mSOD1 (G85R) in neurons develops locomotor dysfunction and severe fecundity defects when compared to transgenic worms expressing human wild-type SOD1. Genetic reduction of aak-2, the ortholog of the AMPK α2 catalytic subunit in nematodes, improved locomotor behavior and fecundity in G85R animals. Similar observations were made with nematodes engineered to express mutant tat-activating regulatory (TAR) DNA-binding protein of 43 kDa molecular weight. Altogether, these data suggest that bioenergetic abnormalities are likely to be pathophysiologically relevant to motor neuron disease. PMID:22262909

Sliding of microtubules by a team of dynein motors: Understanding the effect of spatial distribution of motor tails and mutual exclusion of motor heads on microtubules

NASA Astrophysics Data System (ADS)

Singh, Hanumant Pratap; Takshak, Anjneya; Mall, Utkarsh; Kunwar, Ambarish

2016-06-01

Molecular motors are natural nanomachines that use the free energy released from ATP hydrolysis to generate mechanical forces. Cytoplasmic dynein motors often work collectively as a team to drive important processes such as axonal growth, proplatelet formation and mitosis, as forces generated by single motors are insufficient. A large team of dynein motors is used to slide cytoskeletal microtubules with respect to one another during the process of proplatelet formation and axonal growth. These motors attach to a cargo microtubule via their tail domains, undergo the process of detachment and reattachment of their head domains on another track microtubule, while sliding the cargo microtubule along the track. Traditional continuum/mean-field approaches used in the past are not ideal for studying the sliding mechanism of microtubules, as they ignore spatial and temporal fluctuations due to different possible distributions of motor tails on cargo filament, as well as binding/unbinding of motors from their track. Therefore, these models cannot be used to address important questions such as how the distribution of motor tails on microtubules, or how the mutual exclusion of motor heads on microtubule tracks affects the sliding velocity of cargo microtubule. To answer these, here we use a computational stochastic model where we model each dynein motor explicitly. In our model, we use both random as well as uniform distributions of dynein motors on cargo microtubule, as well as mutual exclusion of motors on microtubule tracks. We find that sliding velocities are least affected by the distribution of motor tails on microtubules, whereas they are greatly affected by mutual exclusion of motor heads on microtubule tracks. We also find that sliding velocity depends on the length of cargo microtubule if mutual exclusion among motor heads is considered.

Effects of Physical Activity on Motor Skills and Cognitive Development in Early Childhood: A Systematic Review

PubMed Central

Wen, Xu; Xiang, Ping

2017-01-01

Objective This study synthesized literature concerning casual evidence of effects of various physical activity programs on motor skills and cognitive development in typically developed preschool children. Methods Electronic databases were searched through July 2017. Peer-reviewed randomized controlled trials (RCTs) examining the effectiveness of physical activity on motor skills and cognitive development in healthy young children (4–6 years) were screened. Results A total of 15 RCTs were included. Of the 10 studies assessing the effects of physical activity on motor skills, eight (80%) reported significant improvements in motor performance and one observed mixed findings, but one failed to promote any beneficial outcomes. Of the five studies investigating the influence of physical activity on cognitive development, four (80%) showed significant and positive changes in language learning, academic achievement, attention, and working memory. Notably, one indicated no significant improvements were observed after the intervention. Conclusions Findings support causal evidence of effects of physical activity on both motor skills and cognitive development in preschool children. Given the shortage of available studies, future research with large representative samples is warranted to explore the relationships between physical activity and cognitive domains as well as strengthen and confirm the dose-response evidence in early childhood. PMID:29387718

Aging Affects Motor Learning but Not Savings at Transfer of Learning

ERIC Educational Resources Information Center

Seidler, Rachael D.

2007-01-01

Two important components of skill learning are the learning process itself (motor acquisition) and the ability to transfer what has been learned to new task variants (motor transfer). Many studies have documented age-related declines in the ability to learn new manual motor skills. In this study, I tested whether the degree of savings at transfer…

Subthalamic nucleus activity optimizes maximal effort motor responses in Parkinson's disease.

PubMed

Anzak, Anam; Tan, Huiling; Pogosyan, Alek; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Hariz, Marwan; Ashkan, Keyoumars; Bogdanovic, Marko; Green, Alexander L; Aziz, Tipu; Brown, Peter

2012-09-01

The neural substrates that enable individuals to achieve their fastest and strongest motor responses have long been enigmatic. Importantly, characterization of such activities may inform novel therapeutic strategies for patients with hypokinetic disorders, such as Parkinson's disease. Here, we ask whether the basal ganglia may play an important role, not only in the attainment of maximal motor responses under standard conditions but also in the setting of the performance enhancements known to be engendered by delivery of intense stimuli. To this end, we recorded local field potentials from deep brain stimulation electrodes implanted bilaterally in the subthalamic nuclei of 10 patients with Parkinson's disease, as they executed their fastest and strongest handgrips in response to a visual cue, which was accompanied by a brief 96-dB auditory tone on random trials. We identified a striking correlation between both theta/alpha (5-12 Hz) and high-gamma/high-frequency (55-375 Hz) subthalamic nucleus activity and force measures, which explained close to 70% of interindividual variance in maximal motor responses to the visual cue alone, when patients were ON their usual dopaminergic medication. Loud auditory stimuli were found to enhance reaction time and peak rate of development of force still further, independent of whether patients were ON or OFF l-DOPA, and were associated with increases in subthalamic nucleus power over a broad gamma range. However, the contribution of this broad gamma activity to the performance enhancements observed was only modest (≤13%). The results implicate frequency-specific subthalamic nucleus activities as substantial factors in optimizing an individual's peak motor responses at maximal effort of will, but much less so in the performance increments engendered by intense auditory stimuli.

Structural equation modeling of motor impairment, gross motor function, and the functional outcome in children with cerebral palsy.

PubMed

Park, Eun-Young; Kim, Won-Ho

2013-05-01

Physical therapy intervention for children with cerebral palsy (CP) is focused on reducing neurological impairments, improving strength, and preventing the development of secondary impairments in order to improve functional outcomes. However, relationship between motor impairments and functional outcome has not been proved definitely. This study confirmed the construct of motor impairment and performed structural equation modeling (SEM) between motor impairment, gross motor function, and functional outcomes of regarding activities of daily living in children with CP. 98 children (59 boys, 39 girls) with CP participated in this cross-sectional study. Mean age was 11 y 5 mo (SD 1 y 9 mo). The Manual Muscle Test (MMT), the Modified Ashworth Scale (MAS), range of motion (ROM) measurement, and the selective motor control (SMC) scale were used to assess motor impairments. Gross motor function and functional outcomes were measured using the Gross Motor Function Measure (GMFM) and the Functional Skills domain of the Pediatric Evaluation of Disability Inventory (PEDI) respectively. Measurement of motor impairment was consisted of strength, spasticity, ROM, and SMC. The construct of motor impairment was confirmed though an examination of a measurement model. The proposed SEM model showed good fit indices. Motor impairment effected gross motor function (β=-.0869). Gross motor function and motor impairment affected functional outcomes directly (β=0.890) and indirectly (β=-0.773) respectively. We confirmed that the construct of motor impairment consist of strength, spasticity, ROM, and SMC and it was identified through measurement model analysis. Functional outcomes are best predicted by gross motor function and motor impairments have indirect effects on functional outcomes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Motor Behavior Activates Bergmann Glial Networks

PubMed Central

Nimmerjahn, Axel; Mukamel, Eran A.; Schnitzer, Mark J.

2010-01-01

SUMMARY Although it is firmly established neuronal activity is a prime determinant of animal behavior, relationships between astrocytic excitation and animal behavior have remained opaque. Cerebellar Bergmann glia are radial astrocytes that are implicated in motor behavior and exhibit Ca2+-excitation. However, Ca2+-excitation in these cells has not previously been studied in behaving animals. Using two-photon microscopy we found that Bergmann glia exhibit three forms of Ca2+-excitation in awake behaving mice. Two of these are ongoing within the cerebellar vermis. During locomotor performance concerted Ca2+-excitation arises in networks of at least hundreds of Bergmann glia extending across several hundred microns or more. Concerted Ca2+-excitation was abolished by anesthesia or blockade of either neural activity or glutamatergic transmission. Thus, large networks of Bergmann glia can be activated by specific animal behaviors and undergo excitation of sufficient magnitude to potentially initiate macroscopic changes in brain dynamics or blood flow. PMID:19447095

The sensory side of post-stroke motor rehabilitation.

PubMed

Bolognini, Nadia; Russo, Cristina; Edwards, Dylan J

2016-04-11

Contemporary strategies to promote motor recovery following stroke focus on repetitive voluntary movements. Although successful movement relies on efficient sensorimotor integration, functional outcomes often bias motor therapy toward motor-related impairments such as weakness, spasticity and synergies; sensory therapy and reintegration is implied, but seldom targeted. However, the planning and execution of voluntary movement requires that the brain extracts sensory information regarding body position and predicts future positions, by integrating a variety of sensory inputs with ongoing and planned motor activity. Neurological patients who have lost one or more of their senses may show profoundly affected motor functions, even if muscle strength remains unaffected. Following stroke, motor recovery can be dictated by the degree of sensory disruption. Consequently, a thorough account of sensory function might be both prognostic and prescriptive in neurorehabilitation. This review outlines the key sensory components of human voluntary movement, describes how sensory disruption can influence prognosis and expected outcomes in stroke patients, reports on current sensory-based approaches in post-stroke motor rehabilitation, and makes recommendations for optimizing rehabilitation programs based on sensory stimulation.

The sensory side of post-stroke motor rehabilitation

PubMed Central

Bolognini, Nadia; Russo, Cristina; Edwards, Dylan J.

2017-01-01

Contemporary strategies to promote motor recovery following stroke focus on repetitive voluntary movements. Although successful movement relies on efficient sensorimotor integration, functional outcomes often bias motor therapy toward motor-related impairments such as weakness, spasticity and synergies; sensory therapy and reintegration is implied, but seldom targeted. However, the planning and execution of voluntary movement requires that the brain extracts sensory information regarding body position and predicts future positions, by integrating a variety of sensory inputs with ongoing and planned motor activity. Neurological patients who have lost one or more of their senses may show profoundly affected motor functions, even if muscle strength remains unaffected. Following stroke, motor recovery can be dictated by the degree of sensory disruption. Consequently, a thorough account of sensory function might be both prognostic and prescriptive in neurorehabilitation. This review outlines the key sensory components of human voluntary movement, describes how sensory disruption can influence prognosis and expected outcomes in stroke patients, reports on current sensory-based approaches in post-stroke motor rehabilitation, and makes recommendations for optimizing rehabilitation programs based on sensory stimulation. PMID:27080070

Convergence of inhibitory neural inputs regulate motor activity in the murine and monkey stomach

PubMed Central

Shaylor, Lara A.; Hwang, Sung Jin; Sanders, Kenton M.

2016-01-01

Inhibitory motor neurons regulate several gastric motility patterns including receptive relaxation, gastric peristaltic motor patterns, and pyloric sphincter opening. Nitric oxide (NO) and purines have been identified as likely candidates that mediate inhibitory neural responses. However, the contribution from each neurotransmitter has received little attention in the distal stomach. The aims of this study were to identify the roles played by NO and purines in inhibitory motor responses in the antrums of mice and monkeys. By using wild-type mice and mutants with genetically deleted neural nitric oxide synthase (Nos1−/−) and P2Y1 receptors (P2ry1−/−) we examined the roles of NO and purines in postjunctional inhibitory responses in the distal stomach and compared these responses to those in primate stomach. Activation of inhibitory motor nerves using electrical field stimulation (EFS) produced frequency-dependent inhibitory junction potentials (IJPs) that produced muscle relaxations in both species. Stimulation of inhibitory nerves during slow waves terminated pacemaker events and associated contractions. In Nos1−/− mice IJPs and relaxations persisted whereas in P2ry1−/− mice IJPs were absent but relaxations persisted. In the gastric antrum of the non-human primate model Macaca fascicularis, similar NO and purine neural components contributed to inhibition of gastric motor activity. These data support a role of convergent inhibitory neural responses in the regulation of gastric motor activity across diverse species. PMID:27634009

Convergence of inhibitory neural inputs regulate motor activity in the murine and monkey stomach.

PubMed

Shaylor, Lara A; Hwang, Sung Jin; Sanders, Kenton M; Ward, Sean M

2016-11-01

Inhibitory motor neurons regulate several gastric motility patterns including receptive relaxation, gastric peristaltic motor patterns, and pyloric sphincter opening. Nitric oxide (NO) and purines have been identified as likely candidates that mediate inhibitory neural responses. However, the contribution from each neurotransmitter has received little attention in the distal stomach. The aims of this study were to identify the roles played by NO and purines in inhibitory motor responses in the antrums of mice and monkeys. By using wild-type mice and mutants with genetically deleted neural nitric oxide synthase (Nos1 -/- ) and P2Y1 receptors (P2ry1 -/- ) we examined the roles of NO and purines in postjunctional inhibitory responses in the distal stomach and compared these responses to those in primate stomach. Activation of inhibitory motor nerves using electrical field stimulation (EFS) produced frequency-dependent inhibitory junction potentials (IJPs) that produced muscle relaxations in both species. Stimulation of inhibitory nerves during slow waves terminated pacemaker events and associated contractions. In Nos1 -/- mice IJPs and relaxations persisted whereas in P2ry1 -/- mice IJPs were absent but relaxations persisted. In the gastric antrum of the non-human primate model Macaca fascicularis, similar NO and purine neural components contributed to inhibition of gastric motor activity. These data support a role of convergent inhibitory neural responses in the regulation of gastric motor activity across diverse species. Copyright © 2016 the American Physiological Society.

Motor Skills and Free-Living Physical Activity Showed No Association Among Preschoolers in 2012 U.S. National Youth Fitness Survey.

PubMed

Loprinzi, Paul D; Frith, Emily

2017-04-01

Albeit limited, some emerging work, using convenience-based samples, has demonstrated that greater motor skill development is associated with higher physical activity among preschool-aged children. The purpose of this study was to evaluate this topic using data from the 2012 National Youth Fitness Survey that included 329 preschool-aged children (3-5 years). Parents proxy-reported their child's physical activity, with motor skill level assessed from the Test of Gross Motor Development-Second Edition (TGMD2). Motor skill levels (Gross Motor Quotient, locomotor or object control) were not associated with preschool free-living physical activity in any analytic model. Thus, in this large sample of preschoolers, contrary to research with older children, motor skill level was not associated with physical activity. Findings are discussed in terms of study limitations of (a) a reliance on parent report of children's physical activity levels and (b) the possibility that physical activity data within the national survey were too limited in range to show possible associations to motor skill development with higher levels of free-living physical activity in preschoolers.

Differential neurotoxic effects of in utero and lactational exposure to hydroxylated polychlorinated biphenyl (OH-PCB 106) on spontaneous locomotor activity and motor coordination in young adult male mice.

PubMed

Haijima, Asahi; Lesmana, Ronny; Shimokawa, Noriaki; Amano, Izuki; Takatsuru, Yusuke; Koibuchi, Noriyuki

2017-01-01

We investigated whether in utero or lactational exposure to 4-hydroxy-2',3,3',4',5'-pentachlorobiphenyl (OH-PCB 106) affects spontaneous locomotor activity and motor coordination in young adult male mice. For in utero exposure, pregnant C57BL/6J mice received 0.05 or 0.5 mg/kg body weight of OH-PCB 106 or corn oil vehicle via gavage every second day from gestational day 10 to 18. For lactational exposure, the different groups of dams received 0.05 or 0.5 mg/kg body weight of OH-PCB 106 or corn oil vehicle via gavage every second day from postpartum day 3 to 13. At 6-7 weeks of age, the spontaneous locomotor activities of male offspring were evaluated for a 24-hr continuous session in a home cage and in an open field for 30-min. Motor coordination function on an accelerating rotarod was also measured. Mice exposed prenatally to OH-PCB 106 showed increased spontaneous locomotor activities during the dark phase in the home cage and during the first 10-min in the open field compared with control mice. Mice exposed lactationally to OH-PCB 106, however, did not show a time-dependent decrease in locomotor activity in the open field. Instead, their locomotor activity increased significantly during the second 10-min block. In addition, mice exposed lactationally to OH-PCB 106 displayed impairments in motor coordination in the rotarod test. These results suggest that perinatal exposure to OH-PCB 106 affects motor behaviors in young adult male mice. Depending on the period of exposure, OH-PCB 106 may have different effects on neurobehavioral development.

Active Motor Training Has Long-term Effects on Infants’ Object Exploration

PubMed Central

Wiesen, Sarah E.; Watkins, Rachel M.; Needham, Amy Work

2016-01-01

Long-term changes in infants’ behavior as a result of active motor training were studied. Thirty-two infants completed three visits to the laboratory. At the first visit, infants were 3 months old and completed an object exploration assessment. Then the experimenter demonstrated the motor training procedures appropriate for the infant’s experimental condition, and parents took home custom infant mittens (either sticky or non-sticky) and a bag of lightweight toys to practice with their infants. Over the course of the following 2 weeks, infants participated in 10 sessions of either active (sticky) or passive (non-sticky) mittens training at home with their parents. Infants who participated in active mittens training wore mittens with the palms covered in Velcro, allowing them to pick up and move around small toys. Infants who participated in passive mittens training wore non-sticky mittens, and their parents moved the toys through their visual fields on their behalf. After completing the training, infants returned to the lab for the second visit. At visit two, infants participated in another object exploration assessment as well as a reaching assessment. Parents returned the training materials to the lab at the second visit, and were told not to continue any specific training regimen from this point forward. Two months later, when infants were about 5.5 months of age, they returned to the lab for a third visit. At the third visit, infants completed the same two assessments as during the second visit. The results of this study indicate that infants who participated in active motor training engaged in more sophisticated object exploration when compared to infants who received passive training. These findings are consistent with others in the literature showing that active motor training at 3 months of age facilitates the processes of object exploration and engagement. The current results and others reveal that the effects of early experience can last long after

Responsiveness of rat fetuses to sibling motor activity: Communication in utero?

PubMed

Brumley, Michele R; Hoagland, Riana; Truong, Melissa; Robinson, Scott R

2018-04-01

Previous research has revealed that fetuses detect and respond to extrauterine stimuli such as maternal movement and speech, but little attention has been cast on how fetuses may directly influence and respond to each other in the womb. This study investigated whether motor activity of E20 rat fetuses influenced the behavior of siblings in utero. Three experiments showed that; (a) contiguous siblings expressed a higher frequency of synchronized movement than noncontiguous siblings; (b) fetuses that lay between two siblings immobilized with curare showed less movement relative to fetuses between saline or uninjected controls; and (c) fetuses between two siblings behaviorally activated by the opioid agonist U50,488 also showed less activity and specific behavioral changes compared to controls. Our findings suggest that rat fetuses are directly impacted by sibling motor activity, and thus that a rudimentary form of communication between siblings may influence the development of fetuses in utero. © 2018 Wiley Periodicals, Inc.

The Relationship between Fundamental Motor Skill Proficiency and Participation in Organized Sports and Active Recreation in Middle Childhood

PubMed Central

Field, Stephanie C.; Temple, Viviene A.

2017-01-01

Motor skill proficiency in middle childhood is associated with higher physical activity levels at that age and is predictive of adolescent physical activity levels. Much of the previous research in this area has used accelerometry in determining these relationships, and as a result, little is known about what physical activities the children are engaging in. Therefore the aim of this study was to examine rates of participation in physical activities, the relationships between motor proficiency and how often children participate, and if there were gender-based differences in participation, motor skills, or the relationship between these variables. Participants were 400 boys and girls (Mean age = 9 years 6 months) in grade 4. Motor skills were assessed using the Test of Gross Motor Development-2 (TGMD-2) and physical activity participation was measured using the Children’s Assessment of Participation and Enjoyment (CAPE). Descriptive statistics, chi-squared analyses, and multivariate analysis of variance (MANOVA) were used to examine activity patterns and whether these patterns differed by gender. Correlation coefficients were used to estimate the relationships between fundamental motor skill proficiency and participation. The boys and girls participated in many of the same activities, but girls were more likely to participate in most of the informal physical activities. More boys than girls participated in team sports, boys participated more frequently in team sports, and the boys’ object control and locomotor skill proficiency were significantly associated with participation in team sports. There were some significant associations between motor skills and participation in specific activities; however it is not clear if participation is developing skillfulness or those who are more skilled are engaging and persisting with particular activities.

Patterns of motor activity in the isolated nerve cord of the octopus arm.

PubMed

Gutfreund, Yoram; Matzner, Henry; Flash, Tamar; Hochner, Binyamin

2006-12-01

The extremely flexible octopus arm provides a unique opportunity for studying movement control in a highly redundant motor system. We describe a novel preparation that allows analysis of the peripheral nervous system of the octopus arm and its interaction with the muscular and mechanosensory elements of the arm's intrinsic muscular system. First we examined the synaptic responses in muscle fibers to identify the motor pathways from the axial nerve cord of the arm to the surrounding musculature. We show that the motor axons project to the muscles via nerve roots originating laterally from the arm nerve cord. The motor field of each nerve is limited to the region where the nerve enters the arm musculature. The same roots also carry afferent mechanosensory information from the intrinsic muscle to the axial nerve cord. Next, we characterized the pattern of activity generated in the dorsal roots by electrically stimulating the axial nerve cord. The evoked activity, although far reaching and long lasting, cannot alone account for the arm extension movements generated by similar electrical stimulation. The mismatch between patterns of activity in the isolated cord and in an intact arm may stem from the involvement of mechanosensory feedback in natural arm extension.

GIRK Channels Modulate Opioid-Induced Motor Activity in a Cell Type- and Subunit-Dependent Manner

PubMed Central

Kotecki, Lydia; Hearing, Matthew; McCall, Nora M.; Marron Fernandez de Velasco, Ezequiel; Pravetoni, Marco; Arora, Devinder; Victoria, Nicole C.; Munoz, Michaelanne B.; Xia, Zhilian; Slesinger, Paul A.; Weaver, C. David

2015-01-01

G-protein-gated inwardly rectifying K+ (GIRK/Kir3) channel activation underlies key physiological effects of opioids, including analgesia and dependence. GIRK channel activation has also been implicated in the opioid-induced inhibition of midbrain GABA neurons and consequent disinhibition of dopamine (DA) neurons in the ventral tegmental area (VTA). Drug-induced disinhibition of VTA DA neurons has been linked to reward-related behaviors and underlies opioid-induced motor activation. Here, we demonstrate that mouse VTA GABA neurons express a GIRK channel formed by GIRK1 and GIRK2 subunits. Nevertheless, neither constitutive genetic ablation of Girk1 or Girk2, nor the selective ablation of GIRK channels in GABA neurons, diminished morphine-induced motor activity in mice. Moreover, direct activation of GIRK channels in midbrain GABA neurons did not enhance motor activity. In contrast, genetic manipulations that selectively enhanced or suppressed GIRK channel function in midbrain DA neurons correlated with decreased and increased sensitivity, respectively, to the motor-stimulatory effect of systemic morphine. Collectively, these data support the contention that the unique GIRK channel subtype in VTA DA neurons, the GIRK2/GIRK3 heteromer, regulates the sensitivity of the mouse mesolimbic DA system to drugs with addictive potential. PMID:25948263

Does changing from a first generation antipsychotic (perphenazin) to a second generation antipsychotic (risperidone) alter brain activation and motor activity? A case report

PubMed Central

2013-01-01

Background In patients with schizophrenia, altered brain activation and motor activity levels are central features, reflecting cognitive impairments and negative symptoms, respectively. Newer studies using nonlinear methods have addressed the severe disturbances in neurocognitive functioning that is regarded as one of the core features of schizophrenia. Our aim was to compare brain activation and motor activity in a patient during pharmacological treatment that was switched from a first- to a second-generation antipsychotic drug. We hypothesised that this change of medication would increase level of responding in both measures. Case presentation We present the case of a 53-year-old male with onset of severe mental illness in adolescence, ICD-10 diagnosed as schizophrenia of paranoid type, chronic form. We compared brain activation and motor activity in this patient during pharmacological treatment with a first-generation (perphenazin), and later switched to a second-generation (risperidone) antipsychotic drug. We used functional magnetic resonance imaging (fMRI) to measure brain activation and wrist worn actigraphy to measure motor activity. Conclusion Our study showed that brain activation decreased in areas critical for cognitive functioning in this patient, when changing from a first to a second generation antipsychotic drug. However the mean motor activity level was unchanged, although risperidone reduced variability, particularly short-term variability from minute to minute. Compared to the results from previous studies, the present findings indicate that changing to a second-generation antipsychotic alters variability measures towards that seen in a control group, but with reduced brain activation, which was an unexpected finding. PMID:23648137

Does changing from a first generation antipsychotic (perphenazin) to a second generation antipsychotic (risperidone) alter brain activation and motor activity? A case report.

PubMed

Berle, Jan Øystein; Løberg, Else-Marie; Fasmer, Ole Bernt

2013-05-06

In patients with schizophrenia, altered brain activation and motor activity levels are central features, reflecting cognitive impairments and negative symptoms, respectively. Newer studies using nonlinear methods have addressed the severe disturbances in neurocognitive functioning that is regarded as one of the core features of schizophrenia. Our aim was to compare brain activation and motor activity in a patient during pharmacological treatment that was switched from a first- to a second-generation antipsychotic drug. We hypothesised that this change of medication would increase level of responding in both measures. We present the case of a 53-year-old male with onset of severe mental illness in adolescence, ICD-10 diagnosed as schizophrenia of paranoid type, chronic form. We compared brain activation and motor activity in this patient during pharmacological treatment with a first-generation (perphenazin), and later switched to a second-generation (risperidone) antipsychotic drug. We used functional magnetic resonance imaging (fMRI) to measure brain activation and wrist worn actigraphy to measure motor activity. Our study showed that brain activation decreased in areas critical for cognitive functioning in this patient, when changing from a first to a second generation antipsychotic drug. However the mean motor activity level was unchanged, although risperidone reduced variability, particularly short-term variability from minute to minute. Compared to the results from previous studies, the present findings indicate that changing to a second-generation antipsychotic alters variability measures towards that seen in a control group, but with reduced brain activation, which was an unexpected finding.

Spatiotemporal relations of primary sensorimotor and secondary motor activation patterns mapped by NIR imaging

PubMed Central

Khan, Bilal; Chand, Pankaj; Alexandrakis, George

2011-01-01

Functional near infrared (fNIR) imaging was used to identify spatiotemporal relations between spatially distinct cortical regions activated during various hand and arm motion protocols. Imaging was performed over a field of view (FOV, 12 x 8.4 cm) including the secondary motor, primary sensorimotor, and the posterior parietal cortices over a single brain hemisphere. This is a more extended FOV than typically used in current fNIR studies. Three subjects performed four motor tasks that induced activation over this extended FOV. The tasks included card flipping (pronation and supination) that, to our knowledge, has not been performed in previous functional magnetic resonance imaging (fMRI) or fNIR studies. An earlier rise and a longer duration of the hemodynamic activation response were found in tasks requiring increased physical or mental effort. Additionally, analysis of activation images by cluster component analysis (CCA) demonstrated that cortical regions can be grouped into clusters, which can be adjacent or distant from each other, that have similar temporal activation patterns depending on whether the performed motor task is guided by visual or tactile feedback. These analyses highlight the future potential of fNIR imaging to tackle clinically relevant questions regarding the spatiotemporal relations between different sensorimotor cortex regions, e.g. ones involved in the rehabilitation response to motor impairments. PMID:22162826

Childhood motor skill proficiency as a predictor of adolescent physical activity.

PubMed

Barnett, Lisa M; van Beurden, Eric; Morgan, Philip J; Brooks, Lyndon O; Beard, John R

2009-03-01

Cross-sectional evidence has demonstrated the importance of motor skill proficiency to physical activity participation, but it is unknown whether skill proficiency predicts subsequent physical activity. In 2000, children's proficiency in object control (kick, catch, throw) and locomotor (hop, side gallop, vertical jump) skills were assessed in a school intervention. In 2006/07, the physical activity of former participants was assessed using the Australian Physical Activity Recall Questionnaire. Linear regressions examined relationships between the reported time adolescents spent participating in moderate-to-vigorous or organized physical activity and their childhood skill proficiency, controlling for gender and school grade. A logistic regression examined the probability of participating in vigorous activity. Of 481 original participants located, 297 (62%) consented and 276 (57%) were surveyed. All were in secondary school with females comprising 52% (144). Adolescent time in moderate-to-vigorous and organized activity was positively associated with childhood object control proficiency. Respective models accounted for 12.7% (p = .001), and 18.2% of the variation (p = .003). Object control proficient children became adolescents with a 10% to 20% higher chance of vigorous activity participation. Object control proficient children were more likely to become active adolescents. Motor skill development should be a key strategy in childhood interventions aiming to promote long-term physical activity.

Non-motor outcomes of subthalamic stimulation in Parkinson's disease depend on location of active contacts.

PubMed

Dafsari, Haidar Salimi; Petry-Schmelzer, Jan Niklas; Ray-Chaudhuri, K; Ashkan, Keyoumars; Weis, Luca; Dembek, Till A; Samuel, Michael; Rizos, Alexandra; Silverdale, Monty; Barbe, Michael T; Fink, Gereon R; Evans, Julian; Martinez-Martin, Pablo; Antonini, Angelo; Visser-Vandewalle, Veerle; Timmermann, Lars

2018-03-16

Subthalamic nucleus (STN) deep brain stimulation (DBS) improves quality of life (QoL), motor, and non-motor symptoms (NMS) in Parkinson's disease (PD). Few studies have investigated the influence of the location of neurostimulation on NMS. To investigate the impact of active contact location on NMS in STN-DBS in PD. In this prospective, open-label, multicenter study including 50 PD patients undergoing bilateral STN-DBS, we collected NMSScale (NMSS), NMSQuestionnaire (NMSQ), Hospital Anxiety and Depression Scale (anxiety/depression, HADS-A/-D), PDQuestionnaire-8 (PDQ-8), Scales for Outcomes in PD-motor examination, motor complications, activities of daily living (ADL), and levodopa equivalent daily dose (LEDD) preoperatively and at 6 months follow-up. Changes were analyzed with Wilcoxon signed-rank/t-test and Bonferroni-correction for multiple comparisons. Although the STN was targeted visually, we employed an atlas-based approach to explore the relationship between active contact locations and DBS outcomes. Based on fused MRI/CT-images, we identified Cartesian coordinates of active contacts with patient-specific Mai-atlas standardization. We computed linear mixed-effects models with x-/y-/z-coordinates as independent, hemispheres as within-subject, and test change scores as dependent variables. NMSS, NMSQ, PDQ-8, motor examination, complications, and LEDD significantly improved at follow-up. Linear mixed-effect models showed that NMS and QoL improvement significantly depended on more medial (HADS-D, NMSS), anterior (HADS-D, NMSQ, PDQ-8), and ventral (HADS-A/-D, NMSS, PDQ-8) neurostimulation. ADL improved more in posterior, LEDD in lateral neurostimulation locations. No relationship was observed for motor examination and complications scores. Our study provides evidence that more anterior, medial, and ventral STN-DBS is significantly related to more beneficial non-motor outcomes. Copyright © 2018. Published by Elsevier Inc.

Spinal atypical protein kinase C activity is necessary to stabilize inactivity-induced phrenic motor facilitation

PubMed Central

Strey, K.A.; Nichols, N.L.; Baertsch, N.A.; Broytman, O.; Baker-Herman, T.L.

2012-01-01

The neural network controlling breathing must establish rhythmic motor output at a level adequate to sustain life. Reduced respiratory neural activity elicits a novel form of plasticity in circuits driving the diaphragm known as inactivity-induced phrenic motor facilitation (iPMF), a rebound increase in phrenic inspiratory output observed once respiratory neural drive is restored. The mechanisms underlying iPMF are unknown. Here, we demonstrate in anesthetized rats that spinal mechanisms give rise to iPMF, and that iPMF consists of at least two mechanistically distinct phases: 1) an early, labile phase that requires atypical PKC (PKCζ and/or PKCΙ/λ) activity to transition to a 2) late, stable phase. Early (but not late) iPMF is associated with increased interactions between PKCζ/Ι and the scaffolding protein ZIP/p62 in spinal regions associated with the phrenic motor pool. Although PKCζ/Ι activity is necessary for iPMF, spinal aPKC activity is not necessary for phrenic long-term facilitation (pLTF) following acute intermittent hypoxia, an activity-independent form of spinal respiratory plasticity. Thus, while iPMF and pLTF both manifest as prolonged increases in phrenic burst amplitude, they arise from distinct spinal cellular pathways. Our data are consistent with the hypotheses that: 1) local mechanisms sense and respond to reduced respiratory-related activity in the phrenic motor pool, and 2) inactivity-induced increases in phrenic inspiratory output require local PKCζ/Ι activity to stabilize into a long-lasting iPMF. Although the physiological role of iPMF is unknown, we suspect that iPMF represents a compensatory mechanism, assuring adequate motor output in a physiological system where prolonged inactivity ends life. PMID:23152633

Effects of glutamine on gastrointestinal motor activity in patients following gastric surgery.

PubMed

Mochiki, Erito; Ohno, Tetsuro; Yanai, Mitsuhiro; Toyomasu, Yoshitaka; Andoh, Hiroyuki; Kuwano, Hiroyuki

2011-04-01

Postoperative ileus (POI) is one of the most common complications of gastrointestinal surgery. The present study was performed to evaluate the effects of glutamine administration on POI after gastric surgery in humans. The subjects were 31 patients who underwent partial distal gastrectomy for gastric cancer and who were randomly assigned to one of two groups based on postoperative treatment: the glutamine group (3 g/day) and the control group. Manometric recording was done 12 days after surgery, and plasma glutamine concentrations were measured preoperatively and on postoperative day 12. Motor activities of the duodenum in the glutamine group were significantly greater than those of the control group in the interdigestive state. The incidence of phase III motor activity (interdigestive migrating motor contractions) in the glutamine group was significantly higher than that in the control group (60 versus 19%). The glutamine group showed a significantly smaller decrease of plasma glutamine levels compared with the control group. Glutamine could act as a motility-recovery agent after gastrectomy in humans.

Can Kinesiological Activities Change "Pure" Motor Development in Preschool Children during One School Year?

PubMed

Krneta, Željko; Casals, Cristina; Bala, Gustav; Madić, Dejan; Pavlović, Slobodan; Drid, Patrik

2015-07-01

The purpose of this study was to evaluate the effects of an additional, organized, and more intensive kinesiological treatment on "pure" motor abilities in preschool children. In the present study an experimental treatment was carried out on a sample of 37 preschool boys by applying kinesiological activities. The 60 minute treatment was applied over a period of one school year (9 months), twice a week. A control group of 31 boys were trained according to the regular program for preschool institutions. Treatment effects were assessed by 8 motor ability tests and 5 anthropometric measures. The significant differences between the groups, which were observed after the final measurement and compared to the initial one, proved that the kinesiological treatment had a positive impact on the general development of "pure" motor abilities. The most significant effect of experimental kinesiological treatment was the improvement in whole body force, flexibility and coordination of preschool boys. These findings, obtained only in one school year, point to the importance of physical exercise and the application of additional kinesiological activities with various modalities, to improve motor development, even morphological growth and development in preschool children. The effects of the perennial application of kinesiological activities, under the supervision of kinesiological professionals, could be beneficial and could form the basis for a better biological and motor development in older age.

Understanding physical (in-) activity, overweight, and obesity in childhood: Effects of congruence between physical self-concept and motor competence.

PubMed

Utesch, T; Dreiskämper, D; Naul, R; Geukes, K

2018-04-12

Both the physical self-concept and actual motor competence are important for healthy future physical activity levels and consequently decrease overweight and obesity in childhood. However, children scoring high on motor competence do not necessarily report high levels of physical self-concept and vice versa, resulting in respective (in-) accuracy also referred to as (non-) veridicality. This study examines whether children's accuracy of physical self-concept is a meaningful predictive factor for their future physical activity. Motor competence, physical self-concept and physical activity were assessed in 3 rd grade and one year later in 4 th grade. Children's weight status was categorized based on WHO recommendations. Polynomial regression with Response surface analyses were conducted with a quasi-DIF approach examining moderating weight status effects. Analyses revealed that children with higher motor competence levels and higher self-perceptions show greater physical activity. Importantly, children who perceive their motor competence more accurately (compared to less) show more future physical activity. This effect is strong for underweight and overweight/obese children, but weak for normal weight children. This study indicates that an accurate self-perception of motor competence fosters future physical activity beyond single main effects, respectively. Hence, the promotion of actual motor competence should be linked with the respective development of accurate self-knowledge.

Fear of movement modulates the feedforward motor control of the affected limb in complex regional pain syndrome (CRPS): A single-case study.

PubMed

Osumi, Michihiro; Sumitani, Masahiko; Otake, Yuko; Morioka, Shu

2018-01-01

Pain-related fear can exacerbate physical disability and pathological pain in complex regional pain syndrome (CRPS) patients. We conducted a kinematic analysis of grasping movements with a pediatric patient suffering from CRPS in an upper limb to investigate how pain-related fear affects motor control. Using a three-dimensional measurement system, we recorded the patient's movement while grasping three vertical bars of different diameters (thin, middle, thick) with the affected and intact hands. We analyzed the maximum grasp distance between the thumb and the index finger (MGD), the peak velocity of the grasp movement (PV), and the time required for the finger opening phase (TOP) and closing phase (TCP). Consequently, the MGD and PV of grasp movements in the affected hand were significantly smaller than those of the intact hand when grasping the middle and thick bars. This might reflect pain-related fear against visual information of the target size which evokes sensation of difficulty in opening fingers widely to grasp the middle and thick bars. Although MGD and PV increased with target size, the TOP was longer in the affected hand when grasping the thick bar. These findings indicate that pain-related fear impairs motor commands that are sent to the musculoskeletal system, subsequently disrupting executed movements and their sensory feedback. Using kinematic analysis, we objectively demonstrated that pain-related fear affects the process of sending motor commands towards the musculoskeletal system in the CRPS-affected hand, providing a possible explanatory model of pathological pain. Copyright © 2017 Elsevier Ltd. All rights reserved.

Firing patterns of spontaneously active motor units in spinal cord-injured subjects

PubMed Central

Zijdewind, Inge; Thomas, Christine K

2012-01-01

Involuntary motor unit activity at low rates is common in hand muscles paralysed by spinal cord injury. Our aim was to describe these patterns of motor unit behaviour in relation to motoneurone and motor unit properties. Intramuscular electromyographic activity (EMG), surface EMG and force were recorded for 30 min from thenar muscles of nine men with chronic cervical SCI. Motor units fired for sustained periods (>10 min) at regular (coefficient of variation ≤ 0.15, CV, n = 19 units) or irregular intervals (CV > 0.15, n = 14). Regularly firing units started and stopped firing independently suggesting that intrinsic motoneurone properties were important for recruitment and derecruitment. Recruitment (3.6 Hz, SD 1.2), maximal (10.2 Hz, SD 2.3, range: 7.5–15.4 Hz) and derecruitment frequencies were low (3.3 Hz, SD 1.6), as were firing rate increases after recruitment (∼20 intervals in 3 s). Once active, firing often covaried, promoting the idea that units received common inputs. Half of the regularly firing units showed a very slow decline (>40 s) in discharge before derecruitment and had interspike intervals longer than their estimated afterhyperpolarisation potential (AHP) duration (estimated by death rate and breakpoint analyses). The other units were derecruited more abruptly and had shorter estimated AHP durations. Overall, regularly firing units had longer estimated AHP durations and were weaker than irregularly firing units, suggesting they were lower threshold units. Sustained firing of units at regular rates may reflect activation of persistent inward currents, visible here in the absence of voluntary drive, whereas irregularly firing units may only respond to synaptic noise. PMID:22310313

Firing patterns of spontaneously active motor units in spinal cord-injured subjects.

PubMed

Zijdewind, Inge; Thomas, Christine K

2012-04-01

Involuntary motor unit activity at low rates is common in hand muscles paralysed by spinal cord injury. Our aim was to describe these patterns of motor unit behaviour in relation to motoneurone and motor unit properties. Intramuscular electromyographic activity (EMG), surface EMG and force were recorded for 30 min from thenar muscles of nine men with chronic cervical SCI. Motor units fired for sustained periods (>10 min) at regular (coefficient of variation ≤ 0.15, CV, n =19 units) or irregular intervals (CV>0.15, n =14). Regularly firing units started and stopped firing independently suggesting that intrinsic motoneurone properties were important for recruitment and derecruitment. Recruitment (3.6 Hz, SD 1.2), maximal (10.2 Hz, SD 2.3, range: 7.5-15.4 Hz) and derecruitment frequencies were low (3.3 Hz, SD 1.6), as were firing rate increases after recruitment (~20 intervals in 3 s). Once active, firing often covaried, promoting the idea that units received common inputs.Half of the regularly firing units showed a very slow decline (>40 s) in discharge before derecruitment and had interspike intervals longer than their estimated after hyperpolarisation potential (AHP) duration (estimated by death rate and breakpoint analyses). The other units were derecruited more abruptly and had shorter estimated AHP durations. Overall, regularly firing units had longer estimated AHP durations and were weaker than irregularly firing units, suggesting they were lower threshold units. Sustained firing of units at regular rates may reflect activation of persistent inward currents, visible here in the absence of voluntary drive, whereas irregularly firing units may only respond to synaptic noise.

Dopamine D1 receptor activation maintains motor coordination and balance in rats.

PubMed

Avila-Luna, Alberto; Gálvez-Rosas, Arturo; Durand-Rivera, Alfredo; Ramos-Languren, Laura-Elisa; Ríos, Camilo; Arias-Montaño, José-Antonio; Bueno-Nava, Antonio

2018-02-01

Dopamine (DA) modulates motor coordination, and its depletion, as in Parkinson's disease, produces motor impairment. The basal ganglia, cerebellum and cerebral cortex are interconnected, have functional roles in motor coordination, and possess dopamine D 1 receptors (D 1 Rs), which are expressed at a particularly high density in the basal ganglia. In this study, we examined whether the activation of D 1 Rs modulates motor coordination and balance in the rat using a beam-walking test that has previously been used to detect motor coordination deficits. The systemic administration of the D 1 R agonist SKF-38393 at 2, 3, or 4 mg/kg did not alter the beam-walking scores, but the subsequent administration of the D 1 R antagonist SCH-23390 at 1 mg/kg did produce deficits in motor coordination, which were reversed by the full agonist SKF-82958. The co-administration of SKF-38393 and SCH-23390 did not alter the beam-walking scores compared with the control group, but significantly prevented the increase in beam-walking scores induced by SCH-23390. The effect of the D 1 R agonist to prevent and reverse the effect of the D 1 R antagonist in beam-walking scores is an indicator that the function of D 1 Rs is necessary to maintain motor coordination and balance in rats. Our results support that D 1 Rs mediate the SCH-23390-induced deficit in motor coordination.

Peer Presence and Sex Differences in Motor Activity Level.

ERIC Educational Resources Information Center

Eaton, Warren O.; Keats, James G.

The hypothesis that boys are more stimulated than girls to high levels of motor activity by the presence of same-sex peers was examined by exposing preschoolers to a standardized setting under two conditions, alone and in triads. If true, the "contagion" effect would result in larger sex differences under the triad condition than under…

Motor cortical activity changes during neuroprosthetic-controlled object interaction.

PubMed

Downey, John E; Brane, Lucas; Gaunt, Robert A; Tyler-Kabara, Elizabeth C; Boninger, Michael L; Collinger, Jennifer L

2017-12-05

Brain-computer interface (BCI) controlled prosthetic arms are being developed to restore function to people with upper-limb paralysis. This work provides an opportunity to analyze human cortical activity during complex tasks. Previously we observed that BCI control became more difficult during interactions with objects, although we did not quantify the neural origins of this phenomena. Here, we investigated how motor cortical activity changed in the presence of an object independently of the kinematics that were being generated using intracortical recordings from two people with tetraplegia. After identifying a population-wide increase in neural firing rates that corresponded with the hand being near an object, we developed an online scaling feature in the BCI system that operated without knowledge of the task. Online scaling increased the ability of two subjects to control the robotic arm when reaching to grasp and transport objects. This work suggests that neural representations of the environment, in this case the presence of an object, are strongly and consistently represented in motor cortex but can be accounted for to improve BCI performance.

Neuron activity in rat hippocampus and motor cortex during discrimination reversal.

PubMed

Disterhoft, J F; Segal, M

1978-01-01

Chronic unit activity and gross movement were recorded from rats during two discrimination reversals in a classical appetitive conditioning situation. The anticipatory movement decreased in response to the former CS+ tone and increased to the previous CS- tone after each reversal. Hippocampus and motor cortex were differently related to these two kinds of behavioral change. Response rates of hippocampal neurons were more closely related to the increased movement response to the former CS- which now signaled food. Motor cortex neuron responses were more closely correlated with the decrease in movement responses to the former CS+ which became neutral after the reversal. It appeared that hippocampal neurons could have been involved in one cognitive aspect of the situation, motor cortex neurons in another. The data were related to current functional concepts of these brain regions.

Esterases activity in the axolotl Ambystoma mexicanum exposed to chlorpyrifos and its implication to motor activity.

PubMed

Robles-Mendoza, Cecilia; Zúñiga-Lagunes, Sebastian R; Ponce de León-Hill, Claudia A; Hernández-Soto, Jesús; Vanegas-Pérez, Cecilia

2011-10-01

The axolotl Ambystoma mexicanum is a neotenic salamander considered a good biological model due to its ability to regenerate limbs, tail, brain and heart cells. Nevertheless, severe reduction of A. mexicanum wild populations in the lacustrine area of Xochimilco, the natural habitat of the axolotl, could be related to several environmental pressures as the presence of organophosphate pesticides (OPPs), intensively applied in agricultural activities in Xochimilco. Thus the aim of this study was to evaluate the effect of environmentally realistic chlorpyrifos (CPF) concentrations, a OPP commonly used in this zone, on esterases activity (acetylcholinesterase and carboxylesterase) and bioconcentration of CPF and to relate them with the motor activity of A. mexicanum juveniles. Axolotls were exposed 48 h to 0.05 and 0.1mg CPF/L, and the responses were evaluated at the end of the CPF exposure. Results suggest that CPF is bioconcentrated into axolotls and that the CPF internal concentrations are related with the observed inhibition activity of AChE (>50%) and CbE (≈ 50%). CPF concentration responsible of the inhibition of the 50% of AChE activity (IC50) was estimated in 0.04 mg CPF/L; however IC50 for CbE activity was not possible to calculate since inhibition levels were lower than 50%, results that suggest a higher resistance of CbE enzymatic activity to CPF. However, motor activity was a more sensitive endpoint to CPF poisoning since time that axolotls spent active and walking, frequency and speed of swimming, frequency of prey attack were reduced >90% of control groups. The motor activity alterations in the axolotl could be related with the registered esterases inhibition. Thus important alterations on axolotls were identified even at short time and low concentrations of CPF exposure. Also, it was possible to link biochemical responses as esterases activity with higher levels of biological organization as behavior. This study provides tools for the regulation of the

Non-Stationarity and Power Spectral Shifts in EMG Activity Reflect Motor Unit Recruitment in Rat Diaphragm Muscle

PubMed Central

Seven, Yasin B.; Mantilla, Carlos B.; Zhan, Wen-Zhi; Sieck, Gary C.

2012-01-01

We hypothesized that diaphragm muscle (DIAm) by a shift in the EMG power spectral density (PSD) to higher frequencies reflects recruitment of more fatigable fast-twitch motor units and motor unit recruitment is reflected by EMG non-stationarity. DIAm EMG was recorded in anesthetized rats during eupnea, hypoxia-hypercapnia (10% O2-5% CO2), airway occlusion, and sneezing (maximal DIAm force). Although power in all frequency bands increased progressively across motor behaviors, PSD centroid frequency increased only during sneezing (p<0.05). The non-stationary period at the onset of EMG activity ranged from ~70 ms during airway occlusion to ~150 ms during eupnea. Within the initial non-stationary period of EMG activity 80–95% of motor units were recruited during different motor behaviors. Motor units augmented their discharge frequencies progressively beyond the non-stationary period; yet, EMG signal became stationary. In conclusion, non-stationarity of DIAm EMG reflects the period of motor unit recruitment, while a shift in the PSD towards higher frequencies reflects recruitment of more fatigable fast-twitch motor units. PMID:22986086

Non-stationarity and power spectral shifts in EMG activity reflect motor unit recruitment in rat diaphragm muscle.

PubMed

Seven, Yasin B; Mantilla, Carlos B; Zhan, Wen-Zhi; Sieck, Gary C

2013-01-15

We hypothesized that a shift in diaphragm muscle (DIAm) EMG power spectral density (PSD) to higher frequencies reflects recruitment of more fatigable fast-twitch motor units and motor unit recruitment is reflected by EMG non-stationarity. DIAm EMG was recorded in anesthetized rats during eupnea, hypoxia-hypercapnia (10% O(2)-5% CO(2)), airway occlusion, and sneezing (maximal DIAm force). Although power in all frequency bands increased progressively across motor behaviors, PSD centroid frequency increased only during sneezing (p<0.05). The non-stationary period at the onset of EMG activity ranged from ∼80 ms during airway occlusion to ∼150 ms during eupnea. Within the initial non-stationary period of EMG activity 80-95% of motor units were recruited during different motor behaviors. Motor units augmented their discharge frequencies progressively beyond the non-stationary period; yet, EMG signal became stationary. In conclusion, non-stationarity of DIAm EMG reflects the period of motor unit recruitment, while a shift in the PSD towards higher frequencies reflects recruitment of more fatigable fast-twitch motor units. Copyright © 2012 Elsevier B.V. All rights reserved.

Corticomotor Responses to Attentionally Demanding Motor Performance: A Mini-Review

PubMed Central

Corp, Daniel  T.; Drury, Hannah G. K.; Young, Kayleigh; Do, Michael; Perkins, Tom; Pearce, Alan J.

2013-01-01

Increased attentional demand has been shown to reduce motor performance, leading to increases in accidents, particularly in elderly populations. While these deficits have been well documented behaviorally, their cortical correlates are less well known. Increased attention has been shown to affect activity in prefrontal regions of the cortex. However there have been varying results within past research investigating corticomotor regions, mediating motor performance. This mini-review initially discusses past behavioral research, before moving to studies investigating corticomotor areas in response to changes in attention. Recent dual task studies have revealed a possible decline in the ability of older, but not younger, adults to activate inhibitory processes within the motor cortex, which may be correlated with poor motor performance, and thus accidents. A reduction in cortical inhibition may be caused by neurodegeneration within prefrontal regions of the cortex with age, rendering older adults less able to allocate attention to corticomotor regions. PMID:23579267

How emotion context modulates unconscious goal activation during motor force exertion.

PubMed

Blakemore, Rebekah L; Neveu, Rémi; Vuilleumier, Patrik

2017-02-01

Priming participants with emotional or action-related concepts influences goal formation and motor force output during effort exertion tasks, even without awareness of priming information. However, little is known about neural processes underpinning how emotional cues interact with action (or inaction) goals to motivate (or demotivate) motor behaviour. In a novel functional neuroimaging paradigm, visible emotional images followed by subliminal action or inaction word primes were presented before participants performed a maximal force exertion. In neutral emotional contexts, maximum force was lower following inaction than action primes. However, arousing emotional images had interactive motivational effects on the motor system: Unpleasant images prior to inaction primes increased force output (enhanced effort exertion) relative to control primes, and engaged a motivation-related network involving ventral striatum, extended amygdala, as well as right inferior frontal cortex. Conversely, pleasant images presented before action (versus control) primes decreased force and activated regions of the default-mode network, including inferior parietal lobule and medial prefrontal cortex. These findings show that emotional context can determine how unconscious goal representations influence motivational processes and are transformed into actual motor output, without direct rewarding contingencies. Furthermore, they provide insight into altered motor behaviour in psychopathological disorders with dysfunctional motivational processes. Copyright © 2016 Elsevier Inc. All rights reserved.

THE ROLE OF MOTOR ACTIVITY IN THE ASSESSMENT OF NEUROTOXICITY

EPA Science Inventory

Motor activity is a behavioral test that has been recommended as a component of testing batteries that evaluate the neurotoxic potential of chemicals. his brief commentary will address the role of this test in such evaluations. t is organized in accordance with the questions that...

Evidence of central cholinergic mechanisms in the appearance of affective aggressive behaviour: dissociation of aggression from autonomic and motor phenomena.

PubMed

Beleslin, D B; Samardzić, R

1979-04-11

Carbachol, muscarine, eserine and neostigmine injected into the cerebral ventricles of conscious cats evoked emotional behaviour with aggression, autonomic and motor phenomena as well as clonic-tonic convulsions. The main and the most impressive feature of the gross behavioural effects of intraventricular carbachol, muscarine, eserine and neostigmine in conscious cats was the affective type of aggression. However, neostigmine produced aggressive behaviour only in about one-quarter of the experiments. After intraventricular hemicholinium-3 and triethylcholine carbachol, muscarine, eserine and neostigmine elicited autonomic and motor phenomena. In these cats cholinomimetics and anticholinesterases evoked only slight hissing and snarling. Choline administered into the cerebral ventricles of hemicholinium-3 and triethylcholine-treated cats restored the emotional behaviour with aggression, autonomic and motor phenomena as well as clonic-tonic convulsions to intraventricular carbachol, muscarine, eserine and neostigmine. The restored gross behavioural changes to eserine were almost of the same intensity, while those to carbachol and muscarine were of lesser intensity than in control cats. From these experiments it is concluded that cholinergic neurones are involved in the appearance of the affective type of aggression resulting from intraventricular carbachol, muscarine, eserine and neostigmine.

Identification by machine vision of the rate of motor activity decline as a lifespan predictor in C. elegans

PubMed Central

Hsu, Ao-Lin; Feng, Zhaoyang; Hsieh, Meng-Yin; Xu, X. Z. Shawn

2009-01-01

One challenge in aging research concerns identifying physiological parameters or biomarkers that can reflect the physical health of an animal and predict its lifespan. In C. elegans, a model organism widely used in aging research, motor deficits develop in old worms. Here we employed machine vision to quantify worm locomotion behavior throughout lifespan. We confirm that aging worms undergo a progressive decline in motor activity, beginning in early life. Importantly, the rate of motor activity decline rather than the absolute motor activity in the early-to-mid life of individual worms in an isogenic population inversely correlates with their lifespan, and thus may serve as a lifespan predictor. Long-lived mutant strains with deficits in insulin/IGF-1 signaling or food intake display a reduction in the rate of motor activity decline, suggesting that this parameter might also be used for across-strain comparison of healthspan. Our work identifies an endogenous physiological parameter for lifespan prediction and healthspan comparison. PMID:18255194

Identification by machine vision of the rate of motor activity decline as a lifespan predictor in C. elegans.

PubMed

Hsu, Ao-Lin; Feng, Zhaoyang; Hsieh, Meng-Yin; Xu, X Z Shawn

2009-09-01

One challenge in aging research concerns identifying physiological parameters or biomarkers that can reflect the physical health of an animal and predict its lifespan. In C. elegans, a model organism widely used in aging research, motor deficits develop in old worms. Here we employed machine vision to quantify worm locomotion behavior throughout lifespan. We confirm that aging worms undergo a progressive decline in motor activity, beginning in early life. Importantly, the rate of motor activity decline rather than the absolute motor activity in the early-to-mid life of individual worms in an isogenic population inversely correlates with their lifespan, and thus may serve as a lifespan predictor. Long-lived mutant strains with deficits in insulin/IGF-1 signaling or food intake display a reduction in the rate of motor activity decline, suggesting that this parameter might also be used for across-strain comparison of healthspan. Our work identifies an endogenous physiological parameter for lifespan prediction and healthspan comparison.

BDNF heightens the sensitivity of motor neurons to excitotoxic insults through activation of TrkB

NASA Technical Reports Server (NTRS)

Hu, Peter; Kalb, Robert G.; Walton, K. D. (Principal Investigator)

2003-01-01

The survival promoting and neuroprotective actions of brain-derived neurotrophic factor (BDNF) are well known but under certain circumstances this growth factor can also exacerbate excitotoxic insults to neurons. Prior exploration of the receptor through which BDNF exerts this action on motor neurons deflects attention away from p75. Here we investigated the possibility that BDNF acts through the receptor tyrosine kinase, TrkB, to confer on motor neurons sensitivity to excitotoxic challenge. We blocked BDNF activation of TrkB using a dominant negative TrkB mutant or a TrkB function blocking antibody, and found that this protected motor neurons against excitotoxic insult in cultures of mixed spinal cord neurons. Addition of a function blocking antibody to BDNF to mixed spinal cord neuron cultures is also neuroprotective indicating that endogenously produced BDNF participates in vulnerability to excitotoxicity. We next examined the intracellular signaling cascades that are engaged upon TrkB activation. Previously we found that inhibition of the phosphatidylinositide-3'-kinase (PI3'K) pathway blocks BDNF-induced excitotoxic sensitivity. Here we show that expression of a constitutively active catalytic subunit of PI3'K, p110, confers excitotoxic sensitivity (ES) upon motor neurons not incubated with BDNF. Parallel studies with purified motor neurons confirm that these events are likely to be occuring specifically within motor neurons. The abrogation of BDNF's capacity to accentuate excitotoxic insults may make it a more attractive neuroprotective agent.

School Physical Activity Programming and Gross Motor Skills in Children.

PubMed

Burns, Ryan D; Fu, You; Hannon, James C; Brusseau, Timothy A

2017-09-01

We examined the effect of a comprehensive school physical activity program (CSPAP) on gross motor skills in children. Participants were 959 children (1st-6th grade; Mean age = 9.1 ± 1.5 years; 406 girls, 553 boys) recruited from 5 low-income schools receiving a year-long CSPAP intervention. Data were collected at the beginning of the school year and at a 36-week follow-up. Gross motor skills were assessed using the Test for Gross Motor Development (3rd ed.) (TGMD-3) instrument. Multi-level mixed effects models were employed to examine the effect of CSPAP on TGMD-3 scores, testing age and sex as effect modifiers and adjusting for clustering of observations within the data structure. There were statistically significant coefficients for time (β = 8.1, 95% CI [3.9, 12.3], p < .001) and an age × time interaction (β = -1.7, 95% CI [-2.3, -1.1], p < .001) on TGMD-3 total scores. Significant improvements were also seen for locomotor skills and ball skills sub-test scores. Children showed improved gross motor skill scores at the end of the 36-week CSPAP that were modified by age, as younger children displayed greater improvements in TGMD-3 scores compared to older children.

Fipronil promotes motor and behavioral changes in honey bees (Apis mellifera) and affects the development of colonies exposed to sublethal doses.

PubMed

Zaluski, Rodrigo; Kadri, Samir Moura; Alonso, Diego Peres; Martins Ribolla, Paulo Eduardo; de Oliveira Orsi, Ricardo

2015-05-01

Bees play a crucial role in pollination and generate honey and other hive products; therefore, their worldwide decline is cause for concern. New broad-spectrum systemic insecticides such as fipronil can harm bees and their use has been discussed as a potential threat to bees' survival. In the present study, the authors evaluate the in vitro toxicity of fipronil and note behavioral and motor activity changes in Africanized adult Apis mellifera that ingest or come into contact with lethal or sublethal doses of fipronil. The effects of sublethal doses on brood viability, population growth, behavior, and the expression of the defensin 1 gene in adult bees were studied in colonies fed with contaminated sugar syrup (8 µg fipronil L(-1) ). Fipronil is highly toxic to bees triggering agitation, seizures, tremors, and paralysis. Bees that are exposed to a lethal or sublethal doses showed reduced motor activity. The number of eggs that hatched, the area occupied by worker eggs, and the number of larvae and pupae that developed were reduced, adult bees showed lethargy, and colonies were abandoned when they were exposed to sublethal doses of fipronil. No change was seen in the bees' expression of defensin 1. The authors conclude that fipronil is highly toxic to honey bees and even sublethal doses may negatively affect the development and maintenance of colonies. © 2015 SETAC.

Relation between cooperative molecular motors and active Brownian particles.

PubMed

Touya, Clément; Schwalger, Tilo; Lindner, Benjamin

2011-05-01

Active Brownian particles (ABPs), obeying a nonlinear Langevin equation with speed-dependent drift and noise amplitude, are well-known models used to describe self-propelled motion in biology. In this paper we study a model describing the stochastic dynamics of a group of coupled molecular motors (CMMs). Using two independent numerical methods, one based on the stationary velocity distribution of the motors and the other one on the local increments (also known as the Kramers-Moyal coefficients) of the velocity, we establish a connection between the CMM and the ABP models. The parameters extracted for the ABP via the two methods show good agreement for both symmetric and asymmetric cases and are independent of N, the number of motors, provided that N is not too small. This indicates that one can indeed describe the CMM problem with a simpler ABP model. However, the power spectrum of velocity fluctuations in the CMM model reveals a peak at a finite frequency, a peak which is absent in the velocity spectrum of the ABP model. This implies richer dynamic features of the CMM model which cannot be captured by an ABP model.

Relation between cooperative molecular motors and active Brownian particles

NASA Astrophysics Data System (ADS)

Touya, Clément; Schwalger, Tilo; Lindner, Benjamin

2011-05-01

Active Brownian particles (ABPs), obeying a nonlinear Langevin equation with speed-dependent drift and noise amplitude, are well-known models used to describe self-propelled motion in biology. In this paper we study a model describing the stochastic dynamics of a group of coupled molecular motors (CMMs). Using two independent numerical methods, one based on the stationary velocity distribution of the motors and the other one on the local increments (also known as the Kramers-Moyal coefficients) of the velocity, we establish a connection between the CMM and the ABP models. The parameters extracted for the ABP via the two methods show good agreement for both symmetric and asymmetric cases and are independent of N, the number of motors, provided that N is not too small. This indicates that one can indeed describe the CMM problem with a simpler ABP model. However, the power spectrum of velocity fluctuations in the CMM model reveals a peak at a finite frequency, a peak which is absent in the velocity spectrum of the ABP model. This implies richer dynamic features of the CMM model which cannot be captured by an ABP model.

Robot-assisted motor activation monitored by time-domain optical brain imaging

NASA Astrophysics Data System (ADS)

Steinkellner, O.; Wabnitz, H.; Schmid, S.; Steingräber, R.; Schmidt, H.; Krüger, J.; Macdonald, R.

2011-07-01

Robot-assisted motor rehabilitation proved to be an effective supplement to conventional hand-to-hand therapy in stroke patients. In order to analyze and understand motor learning and performance during rehabilitation it is desirable to develop a monitor to provide objective measures of the corresponding brain activity at the rehabilitation progress. We used a portable time-domain near-infrared reflectometer to monitor the hemodynamic brain response to distal upper extremity activities. Four healthy volunteers performed two different robot-assisted wrist/forearm movements, flexion-extension and pronation-supination in comparison with an unassisted squeeze ball exercise. A special headgear with four optical measurement positions to include parts of the pre- and postcentral gyrus provided a good overlap with the expected activation areas. Data analysis based on variance of time-of-flight distributions of photons through tissue was chosen to provide a suitable representation of intracerebral signals. In all subjects several of the four detection channels showed a response. In some cases indications were found of differences in localization of the activated areas for the various tasks.

Distribution of Active and Resting Periods in the Motor Activity of Patients with Depression and Schizophrenia

PubMed Central

Hauge, Erik; Berle, Jan Øystein; Dilsaver, Steven; Oedegaard, Ketil J.

2016-01-01

Objective Alterations of activity are prominent features of the major functional psychiatric disorders. Motor activity patterns are characterized by bursts of activity separated by periods with inactivity. The purpose of the present study has been to analyze such active and inactive periods in patients with depression and schizophrenia. Methods Actigraph registrations for 12 days from 24 patients with schizophrenia, 23 with depression and 29 healthy controls. Results Patients with schizophrenia and depression have distinctly different profiles with regard to the characterization and distribution of active and inactive periods. The mean duration of active periods is lowest in the depressed patients, and the duration of inactive periods is highest in the patients with schizophrenia. For active periods the cumulative probability distribution, using lengths from 1 to 35 min, follows a straight line on a log-log plot, suggestive of a power law function, and a similar relationship is found for inactive periods, using lengths from 1 to 20 min. For both active and inactive periods the scaling exponent is higher in the depressed compared to the schizophrenic patients. Conclusion The present findings add to previously published results, with other mathematical methods, suggesting there are important differences in control systems regulating motor behavior in these two major groups of psychiatric disorders. PMID:26766953

Sleep-Active Neurons: Conserved Motors of Sleep

PubMed Central

Bringmann, Henrik

2018-01-01

Sleep is crucial for survival and well-being. This behavioral and physiological state has been studied in all major genetically accessible model animals, including rodents, fish, flies, and worms. Genetic and optogenetic studies have identified several neurons that control sleep, making it now possible to compare circuit mechanisms across species. The “motor” of sleep across animal species is formed by neurons that depolarize at the onset of sleep to actively induce this state by directly inhibiting wakefulness. These sleep-inducing neurons are themselves controlled by inhibitory or activating upstream pathways, which act as the “drivers” of the sleep motor: arousal inhibits “sleep-active” neurons whereas various sleep-promoting “tiredness” pathways converge onto sleep-active neurons to depolarize them. This review provides the first overview of sleep-active neurons across the major model animals. The occurrence of sleep-active neurons and their regulation by upstream pathways in both vertebrate and invertebrate species suggests that these neurons are general and ancient components that evolved early in the history of nervous systems. PMID:29618588