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Sample records for cat motor cortex

  1. Effects of stimulation parameters and electrode location on thresholds for epidural stimulation of cat motor cortex

    Science.gov (United States)

    Wongsarnpigoon, Amorn; Grill, Warren M.

    2011-12-01

    Epidural electrical stimulation (ECS) of the motor cortex is a developing therapy for neurological disorders. Both placement and programming of ECS systems may affect the therapeutic outcome, but the treatment parameters that will maximize therapeutic outcomes and minimize side effects are not known. We delivered ECS to the motor cortex of anesthetized cats and investigated the effects of electrode placement and stimulation parameters on thresholds for evoking motor responses in the contralateral forelimb. Thresholds were inversely related to stimulation frequency and the number of pulses per stimulus train. Thresholds were lower over the forelimb representation in motor cortex (primary site) than surrounding sites (secondary sites), and thresholds at sites 4 mm away. Electrode location and montage influenced the effects of polarity on thresholds: monopolar anodic and cathodic thresholds were not significantly different over the primary site, cathodic thresholds were significantly lower than anodic thresholds over secondary sites and bipolar thresholds were significantly lower with the anode over the primary site than with the cathode over the primary site. A majority of bipolar thresholds were either between or equal to the respective monopolar thresholds, but several bipolar thresholds were greater than or less than the monopolar thresholds of both the anode and cathode. During bipolar stimulation, thresholds were influenced by both electric field superposition and indirect, synaptically mediated interactions. These results demonstrate the influence of stimulation parameters and electrode location during cortical stimulation, and these effects should be considered during the programming of systems for therapeutic cortical stimulation.

  2. On the Nature of the Intrinsic Connectivity of the Cat Motor Cortex: Evidence for a Recurrent Neural Network Topology

    DEFF Research Database (Denmark)

    Capaday, Charles; Ethier, C; Brizzi, L;

    2009-01-01

    Capaday C, Ethier C, Brizzi L, Sik A, van Vreeswijk C, Gingras D. On the nature of the intrinsic connectivity of the cat motor cortex: evidence for a recurrent neural network topology. J Neurophysiol 102: 2131-2141, 2009. First published July 22, 2009; doi: 10.1152/jn.91319.2008. The details...... and functional significance of the intrinsic horizontal connections between neurons in the motor cortex (MCx) remain to be clarified. To further elucidate the nature of this intracortical connectivity pattern, experiments were done on the MCx of three cats. The anterograde tracer biocytin was ejected...

  3. Neural mechanism of activity spread in the cat motor cortex and its relation to the intrinsic connectivity

    DEFF Research Database (Denmark)

    Capaday, Charles; van Vreeswijk, Carl; Ethier, Christian;

    2011-01-01

    to be determined. To address these issues, an 8 x 8 microelectrode array was inserted in the forelimb area of the cat motor cortex (MCx). The centre of the array had a laser etched hole ∼500 {#956}m in diameter. A microiontophoretic pipette, with a tip diameter of 2–3 {#956}m, containing bicuculline methiodide...

  4. Effects of torque disturbances on elbow joint movements evoked in unanesthetized cats by microstimulation of the motor cortex.

    Science.gov (United States)

    Kostyukov, A I; Tal'nov, A N

    1991-01-01

    Flexion and extension movements were evoked in the elbow joint of unanesthetized cats by intracortical microstimulation (ICMS) applied to deep layers of the motor cortex (areas 4 and 6). Pulse trains with duration up to 3-4 s, current intensities of 15-50 microA and rates of approximately 100/s were used. Cortically evoked movements (CEMs) were tested mechanically by applying servo-controlled torque disturbances to the joint. The disturbances consisted of two reciprocating sinusoidal pulses of torque with fixed frequencies (1.2 or 3.2 Hz). A pronounced torque-angle hysteresis with long-lasting after-effects was revealed in the presence of the torque disturbances that opposed the CEMs and/or assisted them. Two parameters were introduced to describe the mechanical testing of the CEMs quantitatively: (1) the resulting stiffness (RS) defined during the forward and reverse phases of the disturbed movement as a ratio between the amplitudes of torque wave and the overall change of angle at these phases; (2) uncertainty index (UI) defined as the subtraction of forward and reverse angle changes, which was normalized by the first of these two values. RS was shown to be dependent on the immediate past movement history of the joint, it increased with changes in the direction of movement, and its magnitude during such changes could be several times higher than when the disturbance was in the same direction as the movement.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2065744

  5. Activity of the motor cortex during scratching.

    Science.gov (United States)

    Sirota, Mikhail G; Pavlova, Galina A; Beloozerova, Irina N

    2006-02-01

    In awake cats sitting with the head restrained, scratching was evoked using stimulation of the ear. Cats scratched the shoulder area, consistently failing to reach the ear. Kinematics of the hind limb movements and the activity of ankle muscles, however, were similar to those reported earlier in unrestrained cats. The activity of single neurons in the hind limb representation of the motor cortex, including pyramidal tract neurons (PTNs), was examined. During the protraction stage of the scratch response, the activity in 35% of the neurons increased and in 50% decreased compared with rest. During the rhythmic stage, the motor cortex population activity was approximately two times higher compared with rest, because the activity of 53% of neurons increased and that of 33% decreased in this stage. The activity of 61% of neurons was modulated in the scratching rhythm. The average depth of frequency modulation was 12.1 +/- 5.3%, similar to that reported earlier for locomotion. The phases of activity of different neurons were approximately evenly distributed over the scratch cycle. There was no simple correlation between resting receptive field properties and the activity of neurons during the scratch response. We conclude that the motor cortex participates in both the protraction and the rhythmic stages of the scratch response. PMID:16236789

  6. Avalanche Analysis from Multielectrode Ensemble Recordings in Cat, Monkey, and Human Cerebral Cortex during Wakefulness and Sleep

    OpenAIRE

    Nima eDehghani; Hatsopoulos, Nicholas G.; Haga, Zach D.; Rebecca eParker; Bradley eGreger; Eric eHalgren; Sydney S Cash; Alain eDestexhe

    2012-01-01

    Self-organized critical states are found in many natural systems, from earthquakes to forest fires, they have also been observed in neural systems, particularly, in neuronal cultures. However, the presence of critical states in the awake brain remains controversial. Here, we compared avalanche analyses performed on different in vivo preparations during wakefulness, slow-wave sleep, and REM sleep, using high density electrode arrays in cat motor cortex (96 electrodes), monkey motor cortex and ...

  7. Delayed-alternation performance after selective lesions within the prefrontal cortex of the cat.

    Science.gov (United States)

    Markowitsch, H J; Pritzel, M; Kessler, J; Guldin, W; Freeman, R B

    1980-02-01

    On the basis of new neuroanatomical findings on relationships between subregions of the mediodorsal thalamic nucleus and the prefrontal cortex of the cat, it was attempted to investigate the relative importance of prefrontal subfields with the aim of obtaining evidence in favor of a functional inequality of different prefrontal subfields. Four areas, named presylvian (PRS), proreal (PR), dorsomedial (DM), and orbito-insular (OI) sectors, were ablated successfully in 30 adult animals. Performance of a 10-sec delayed-alternation task was compared pre- and postoperatively. Furthermore, most of the cats had to learn an extension of this task postoperatively, using a 20-sec delay period, and lastly, these animals were subjected to an extinction test. Significant performance differences were obtained between cats of different groups in all three tasks. Lesions of subregion PR, and even more of subregion PRS, led to severe behavioral deterioration, whereas lesions of subregion OI were without effect, when compared with the behavior of a sham-operated control group. PRS-cats, furthermore, showed motor disturbances during the first postoperative week. The results obtained suggest that it is possible to subdivide the cat's prefrontal cortex functionally. In addition, it is hypothesized that behavioral changes in cats of groups PRS and PR are due to an inability to use kinesthetic information properly. PMID:7284081

  8. Network and external perturbation induce burst synchronisation in cat cerebral cortex

    Science.gov (United States)

    Lameu, Ewandson L.; Borges, Fernando S.; Borges, Rafael R.; Batista, Antonio M.; Baptista, Murilo S.; Viana, Ricardo L.

    2016-05-01

    The brain of mammals are divided into different cortical areas that are anatomically connected forming larger networks which perform cognitive tasks. The cat cerebral cortex is composed of 65 areas organised into the visual, auditory, somatosensory-motor and frontolimbic cognitive regions. We have built a network of networks, in which networks are connected among themselves according to the connections observed in the cat cortical areas aiming to study how inputs drive the synchronous behaviour in this cat brain-like network. We show that without external perturbations it is possible to observe high level of bursting synchronisation between neurons within almost all areas, except for the auditory area. Bursting synchronisation appears between neurons in the auditory region when an external perturbation is applied in another cognitive area. This is a clear evidence that burst synchronisation and collective behaviour in the brain might be a process mediated by other brain areas under stimulation.

  9. Motor cortex neuroplasticity following brachial plexus transfer

    Directory of Open Access Journals (Sweden)

    Michael Biggs

    2013-08-01

    Full Text Available In the past decade, research has demonstrated that cortical plasticity, once thought only to exist in the early stages of life, does indeed continue on into adulthood. Brain plasticity is now acknowledged as a core principle of brain function and describes the ability of the central nervous system to adapt and modify its structural organization and function as an adaptive response to functional demand. In this clinical case study we describe how we used neuroimaging techniques to observe the functional topographical expansion of a patch of cortex along the sensorimotor cortex of a 27 year-old woman following brachial plexus transfer surgery to re-innervate her left arm. We found bilateral activations present in the thalamus, caudate, insula as well as across the sensorimotor cortex during an elbow flex motor task. In contrast we found less activity in the sensorimotor cortex for a finger tap motor task in addition to activations lateralised to the left inferior frontal gyrus and thalamus and bilaterally for the insula. From a pain perspective the patient who had experienced extensive phantom limb pain before surgery found these sensations were markedly reduced following transfer of the right brachial plexus to the intact left arm. Within the context of this clinical case the results suggest that functional improvements in limb mobility are associated with increased activation in the sensorimotor cortex as well as reduced phantom limb pain.

  10. Anodic or cathodic motor cortex stimulation for pain?

    NARCIS (Netherlands)

    Holsheimer, J.; Manola, L.

    2006-01-01

    Objective. In motor cortex stimulation (MCS) for central and trigeminal pain Resume leads are placed epidurally over the motor and sensory cortex. Several bipolar combinations are used to identify the cortical target corresponding to the painful body segment. The cathode giving the largest motor r

  11. Forelimb training drives transient map reorganization in ipsilateral motor cortex.

    Science.gov (United States)

    Pruitt, David T; Schmid, Ariel N; Danaphongse, Tanya T; Flanagan, Kate E; Morrison, Robert A; Kilgard, Michael P; Rennaker, Robert L; Hays, Seth A

    2016-10-15

    Skilled motor training results in reorganization of contralateral motor cortex movement representations. The ipsilateral motor cortex is believed to play a role in skilled motor control, but little is known about how training influences reorganization of ipsilateral motor representations of the trained limb. To determine whether training results in reorganization of ipsilateral motor cortex maps, rats were trained to perform the isometric pull task, an automated motor task that requires skilled forelimb use. After either 3 or 6 months of training, intracortical microstimulation (ICMS) mapping was performed to document motor representations of the trained forelimb in the hemisphere ipsilateral to that limb. Motor training for 3 months resulted in a robust expansion of right forelimb representation in the right motor cortex, demonstrating that skilled motor training drives map plasticity ipsilateral to the trained limb. After 6 months of training, the right forelimb representation in the right motor cortex was significantly smaller than the representation observed in rats trained for 3 months and similar to untrained controls, consistent with a normalization of motor cortex maps. Forelimb map area was not correlated with performance on the trained task, suggesting that task performance is maintained despite normalization of cortical maps. This study provides new insights into how the ipsilateral cortex changes in response to skilled learning and may inform rehabilitative strategies to enhance cortical plasticity to support recovery after brain injury. PMID:27392641

  12. Avalanche analysis from multi-electrode ensemble recordings in cat, monkey and human cerebral cortex during wakefulness and sleep.

    Directory of Open Access Journals (Sweden)

    Nima eDehghani

    2012-08-01

    Full Text Available Self-organized critical states are found in many natural systems, from earthquakes to forest fires, they have also been observed in neural systems, particularly, in neuronal cultures. However, the presence of critical states in the awake brain remains controversial. Here, we compared avalanche analyses performed on different in vivo preparations during wakefulness, slow-wave sleep and REM sleep, using high-density electrode arrays in cat motor cortex (96 electrodes, monkey motor cortex and premotor cortex and human temporal cortex (96 electrodes in epileptic patients. In neuronal avalanches defined from units (up to 160 single units, the size of avalanches never clearly scaled as power-law, but rather scaled exponentially or displayed intermediate scaling. We also analyzed the dynamics of local field potentials (LFPs and in particular LFP negative peaks (nLFPs among the different electrodes (up to 96 sites in temporal cortex or up to 128 sites in adjacent motor and pre-motor cortices. In this case, the avalanches defined from nLFPs displayed power-law scaling in double logarithmic representations, as reported previously in monkey. However, avalanche defined as positive LFP (pLFP peaks, which are less directly related to neuronal firing, also displayed apparent power-law scaling. Closer examination of this scaling using the more reliable cumulative distribution function (CDF and other rigorous statistical measures, did not confirm power-law scaling. The same pattern was seen for cats, monkey and human, as well as for different brain states of wakefulness and sleep. We also tested other alternative distributions. Multiple exponential fitting yielded optimal fits of the avalanche dynamics with bi-exponential distributions. Collectively, these results show no clear evidence for power-law scaling or self-organized critical states in the awake and sleeping brain of mammals, from cat to man.

  13. The Development and Activity-Dependent Expression of Aggrecan in the Cat Visual Cortex

    OpenAIRE

    Kind, P. C.; Sengpiel, F.; Beaver, C. J.; Crocker-Buque, A.; Kelly, G. M.; R. T. Matthews; Mitchell, D E

    2012-01-01

    The Cat-301 monoclonal antibody identifies aggrecan, a chondroitin sulfate proteoglycan in the cat visual cortex and dorsal lateral geniculate nucleus (dLGN). During development, aggrecan expression increases in the dLGN with a time course that matches the decline in plasticity. Moreover, examination of tissue from selectively visually deprived cats shows that expression is activity dependent, suggesting a role for aggrecan in the termination of the sensitive period. Here, we demonstrate for ...

  14. Mechanisms of hyperpolarization in regenerated mature motor axons in cat

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Krarup, Christian

    2004-01-01

    We found persistent abnormalities in the recovery of membrane excitability in long-term regenerated motor nerve fibres in the cat as indicated in the companion paper. These abnormalities could partly be explained by membrane hyperpolarization. To further investigate this possibility, we compared...... the changes in excitability in control nerves and long-term regenerated cat nerves (3-5 years after tibial nerve crush) during manoeuvres known to alter axonal membrane Na(+)-K(+) pump function: polarization, cooling to 20 degrees C, reperfusion after 10 min ischaemia, and up to 60 s of repetitive stimulation...

  15. Can lesions to the motor cortex induce amyotrophic lateral sclerosis?

    Science.gov (United States)

    Rosenbohm, Angela; Kassubek, Jan; Weydt, Patrick; Marroquin, Nicolai; Volk, Alexander E; Kubisch, Christian; Huppertz, Hans-Jürgen; Weber, Markus; Andersen, Peter M; Weishaupt, Jochen H; Ludolph, Albert C

    2014-02-01

    A recent staging effort for amyotrophic lateral sclerosis (ALS) has demonstrated that the TDP-43 neuropathology may initiate focally in the motor cortex in the majority of patients. We searched our data bank for patients with lesions of the motor cortex which preceded disease onset. We performed a search of our patient- and MRI-data bank and screened 1,835 patients with amyotrophic lateral sclerosis for frontal lobe/motor cortex lesions. We found 18 patients with definite ALS who had documented and defined lesions of the motor cortex, which preceded the initial ALS symptoms by 8-42 years. In the vast majority (15/18) of the patients, the onset of ALS was closely related to the focal lesion since it started in a body region reflecting the damaged cortical area. The findings suggest that initial lesions to the motor cortex may be a contributing initiating factor in some patients with ALS or determine the site of onset in individuals pre-disposed to ALS. PMID:24253481

  16. Age-related changes of structures in cerebellar cortex of cat

    Indian Academy of Sciences (India)

    Changzheng Zhang; Tianmiao Hua; Zaiman Zhu; Xun Luo

    2006-03-01

    We studied the structures of the cerebellar cortex of young adult and old cats for age-related changes, which were statistically analysed. Nissl staining was used to visualize the cortical neurons. The immunohistochemical method was used to display glial fibrillary acidic protein (GFAP)-immunoreactive (IR) astrocytes and neurofilament-immunoreactive (NF-IR) neurons. Under the microscope, the thickness of the cerebellar cortex was measured; and the density of neurons in all the layers as well as that of GFAP-IR cells in the granular layer was analysed. Compared with young adult cats, the thickness of the molecular layer and total cerebellar cortex was significantly decreased in old cats, and that of the granular layer increased. The density of neurons in each layer was significantly lower in old cats than in young adult ones. Astrocytes in old cats were significantly denser than in young adult ones, and accompanied by evident hypertrophy of the cell bodies and enhanced immunoreaction of GFAP substance. Purkinje cells (PCs) in old cats showed much fewer NF-IR dendrites than those in young adults. The above findings indicate a loss of neurons and decrease in the number of dendrites of the PCs in the aged cerebellar cortex, which might underlie the functional decline of afferent efficacy and information integration in the senescent cerebellum. An age-dependent enhancement of activity of the astrocytes may exert a protective effect on neurons in the aged cerebellum.

  17. Motor cortex guides selection of predictable movement targets

    Science.gov (United States)

    Woodgate, Philip J.W.; Strauss, Soeren; Sami, Saber A.; Heinke, Dietmar

    2016-01-01

    The present paper asks whether the motor cortex contributes to prediction-based guidance of target selection. This question was inspired by recent evidence that suggests (i) recurrent connections from the motor system into the attentional system may extract movement-relevant perceptual information and (ii) that the motor cortex cannot only generate predictions of the sensory consequences of movements but may also operate as predictor of perceptual events in general. To test this idea we employed a choice reaching task requiring participants to rapidly reach and touch a predictable or unpredictable colour target. Motor cortex activity was modulated via transcranial direct current stimulation (tDCS). In Experiment 1 target colour repetitions were predictable. Under such conditions anodal tDCS facilitated selection versus sham and cathodal tDCS. This improvement was apparent for trajectory curvature but not movement initiation. Conversely, where no predictability of colour was embedded reach performance was unaffected by tDCS. Finally, the results of a key-press experiment suggested that motor cortex involvement is restricted to tasks where the predictable target colour is movement-relevant. The outcomes are interpreted as evidence that the motor system contributes to the top-down guidance of selective attention to movement targets. PMID:25835319

  18. Long-term motor cortex stimulation for phantom limb pain.

    Science.gov (United States)

    Pereira, Erlick A C; Moore, Tom; Moir, Liz; Aziz, Tipu Z

    2015-04-01

    We present the long-term course of motor cortex stimulation to relieve a case of severe burning phantom arm pain after brachial plexus injury and amputation. During 16-year follow-up the device continued to provide efficacious analgesia. However, several adjustments of stimulation parameters were required, as were multiple pulse generator changes, antibiotics for infection and one electrode revision due to lead migration. Steady increases in stimulation parameters over time were required. One of the longest follow-ups of motor cortex stimulation is described; the case illustrates challenges and pitfalls in neuromodulation for chronic pain, demonstrating strategies for maintaining analgesia and overcoming tolerance. PMID:25340991

  19. Towards a circuit mechanism for movement tuning in motor cortex

    Directory of Open Access Journals (Sweden)

    Thomas C Harrison

    2013-01-01

    Full Text Available The firing rates of neurons in primate motor cortex have been related to multiple parameters of voluntary movement. This finding has been corroborated by stimulation-based studies that have mapped complex movements in rodent and primate motor cortex. However, it has been difficult to link the movement tuning of a neuron with its role within the cortical microcircuit. In sensory cortex, neuronal tuning is largely established by afferents delivering information from tuned receptors in the periphery. Motor cortex, which lacks the granular input layer, may be better understood by analyzing its efferent projections. As a primary source of cortical output, layer 5 neurons represent an ideal starting point for this line of experimentation. It is in these deep output layers that movements can most effectively be evoked by intracortical microstimulation and recordings can obtain the most useful signals for the control of motor prostheses. Studies focused on layer 5 output neurons have revealed that projection identity is a fundamental property related to the laminar position, receptive field and ion channel complement of these cells. Given the variety of brain areas targeted by layer 5 output neurons, knowledge of a neuron’s downstream connectivity may provide insight into its movement tuning. Future experiments that relate motor behavior to the activity of neurons with a known projection identity will yield a more detailed understanding of the function of cortical microcircuits.

  20. Motor cortex electric stimulation for the treatment of neuropathic pain

    OpenAIRE

    Walter J. Fagundes-Pereyra; Manoel Jacobsen Teixeira; Nicolas Reyns; Gustavo Touzet; Sérgio Dantas; Emmanuelle Laureau; Serge Blond

    2010-01-01

    OBJECTIVE: Motor cortex stimulation (MCS) is considered to be an effective treatment for chronic neuropathic pain. The aim of the present study was to assess the efficacy of MCS for treating neuropathic pain. METHOD: 27 patients with chronic neuropathic pain were operated. Electrodes were implanted with the use of an stereotactic frame. Electrophysiological evaluations (motor stimulation and somatosensory evoked potentials) were performed, with guidance by means of three-dimensional reconstru...

  1. Rat whisker motor cortex is subdivided into sensory-input and motor-output areas

    OpenAIRE

    Smith, Jared B.; Alloway, Kevin D.

    2013-01-01

    Rodent whisking is an exploratory behavior that can be modified by sensory feedback. Consistent with this, many whisker-sensitive cortical regions project to agranular motor [motor cortex (MI)] cortex, but the relative topography of these afferent projections has not been established. Intracortical microstimulation (ICMS) evokes whisker movements that are used to map the functional organization of MI, but no study has compared the whisker-related inputs to MI with the ICMS sites that evoke wh...

  2. Induction of motor associative plasticity in the posterior parietal cortex-primary motor network

    DEFF Research Database (Denmark)

    Chao, Chi-Chao; Karabanov, Anke Ninija; Paine, Rainer;

    2015-01-01

    There is anatomical and functional connectivity between the primary motor cortex (M1) and posterior parietal cortex (PPC) that plays a role in sensorimotor integration. In this study, we applied corticocortical paired-associative stimuli to ipsilateral PPC and M1 (parietal ccPAS) in healthy right...

  3. Cortico-cortical connections of the motor cortex in the brushtailed possum (Trichosurus vulpecula).

    OpenAIRE

    Joschko, M A; Sanderson, K J

    1987-01-01

    Cortico-cortical connections of motor cortex in the marsupial brushtailed possum were traced by making injections of horseradish peroxidase (HRP) into two parts of motor cortex: the rostral agranular part which does not overlap somatosensory cortex, and the caudal part which does. Following injections in motor cortex, labelled neurons were observed on the same side of the brain within somatosensory areas 1 and 2 and in parietal cortex just caudal to S1, with most neurons in cortical Layers 2-...

  4. Neural Dynamics and Information Representation in Microcircuits of Motor Cortex

    Directory of Open Access Journals (Sweden)

    Yasuhiro eTsubo

    2013-05-01

    Full Text Available The brain has to analyze and respond to external events that can change rapidly from time to time, suggesting that information processing by the brain may be essentially dynamic rather than static. The dynamical features of neural computation are of significant importance in motor cortex that governs the process of movement generation and learning. In this paper, we discuss these features based primarily on our recent findings on neural dynamics and information coding in the microcircuit of rat motor cortex. In fact, cortical neurons show a variety of dynamical behavior from rhythmic activity in various frequency bands to highly irregular spike firing. Of particular interest are the similarity and dissimilarity of the neuronal response properties in different layers of motor cortex. By conducting electrophysiological recordings in slice preparation, we report the phase response curves of neurons in different cortical layers to demonstrate their layer-dependent synchronization properties. We then study how motor cortex recruits task-related neurons in different layers for voluntary arm movements by simultaneous juxtacellular and multiunit recordings from behaving rats. The results suggest an interesting difference in the spectrum of functional activity between the superficial and deep layers. Furthermore, the task-related activities recorded from various layers exhibited power law distributions of inter-spike intervals (ISIs, in contrast to a general belief that ISIs obey Poisson or Gamma distributions in cortical neurons. We present a theoretical argument that this power law of in vivo neurons may represent the maximization of the entropy of firing rate with limited energy consumption of spike generation. Though further studies are required to fully clarify the functional implications of this coding principle, it may shed new light on information representations by neurons and circuits in motor cortex.

  5. A systematic review of non-motor rTMS induced motor cortex plasticity

    Directory of Open Access Journals (Sweden)

    Gregory Nordmann

    2015-07-01

    Full Text Available Motor cortex excitability can be measured by single- and paired-pulse transcranial magnetic stimulation (TMS. Repetitive transcranial magnetic stimulation (rTMS can induce neuroplastic effects in stimulated and in functionally connected cortical regions. Due to its ability to non-invasively modulate cortical activity, rTMS has been investigated for the treatment of various neurological and psychiatric disorders. However, such studies revealed a high variability of both clinical and neuronal effects induced by rTMS. In order to better elucidate this meta-plasticity, rTMS-induced changes in motor cortex excitability have been monitored in various studies in a pre-post stimulation design. Here, we give a systematic literature review (April 2014 of 29 studies investigating motor cortex excitability changes as a neuronal marker for rTMS effects over non-motor cortical areas. The majority of the studies focused on the stimulation of one of three separate cortical areas: the prefrontal area (17 studies, the cerebellum (8 studies, or the temporal cortex (3 studies. One study assessed the effects of multi-site rTMS. Most studies investigated healthy controls but some also stimulated patients with neuropsychiatric conditions (e.g., affective disorders, tinnitus. Methods and findings of the identified studies were highly variable showing no clear systematic pattern of interaction of non-motor rTMS with measures of motor cortex excitability. Based on the available literature, the measurement of motor cortex excitability changes before and after non-motor rTMS has only limited value in the investigation of rTMS related meta-plasticity as a neuronal state or as a trait marker for neuropsychiatric diseases. Our results do not suggest that there are systematic alterations of cortical excitability changes during rTMS treatment, which calls into question the practice of re-adjusting the stimulation intensity according to the motor threshold over the course of the

  6. Traversing Scales: Large Scale Simulation of the Cat Cortex Using Single Neuron Models

    Czech Academy of Sciences Publication Activity Database

    Vejmelka, Martin; Fründ, I.; Pillai, A.

    Berlin: Springer-Verlag, 2008 - (Graben, P.; Zhou, C.; Thiel, M.; Kurths, J.), s. 331-342. (Understanding Complex Systems). ISBN 978-3-540-73158-0 Institutional research plan: CEZ:AV0Z10300504 Keywords : cat cortex * large scale simulation * single neuron models * spiking models * complex networks * neural connectivity * signal propagation Subject RIV: IN - Informatics, Computer Science

  7. Dopaminergic Meso-Cortical Projections to M1: Role in Motor Learning and Motor Cortex Plasticity

    OpenAIRE

    JonasAurelHosp

    2013-01-01

    Although the architecture of a dopaminergic (DA) system within the primary motor cortex (M1) was well characterized anatomically, its functional significance remained obscure for a long time. Recent studies in rats revealed that the integrity of DA fibers in M1 is a prerequisite for successful acquisition of motor skills. This essential contribution of DA for motor learning is plausible as it modulates M1 circuitry at multiple levels thereby promoting plastic changes that are required for inf...

  8. Motor cortex stimulation therapy for post-stroke weakness

    International Nuclear Information System (INIS)

    Motor cortex stimulation (MCS) delivered concurrently with rehabilitation therapy may enhance motor recovery following stroke. We investigated the effects of MCS on the recovery from upper extremity paresis in patients with chronic stroke. In 12 patients who had moderate arm and finger paresis at more than 4 months after stroke, an electrode was placed through a small craniotomy on the epidural space of the motor cortex that was identified using functional MRI. MCS during occupational therapy for one hour was performed 3 times a day for at least 4 weeks. The mean scores for Fugl-Meyer assessments of the arm improved, from 37 preoperatively to 46 postoperatively. The mean grip strength improved from 3.25 to 9.0 kg. All patients appeared satisfactory in their results because they recognized an improvement of arm function. Although the mechanism of the beneficial effects of MCS on recovery after stroke has not been well known, the neuroplasticity might play a important role. In a few cases of the present series, it was observed that the hand motor cortex area detected on functional MRI had been enlarged after MCS therapy. MCS could become a novel neurosurgical treatment modality for the chronic post-stroke weakness. (author)

  9. Differential expression of molecular motors in the motor cortex of sporadic ALS.

    Science.gov (United States)

    Pantelidou, Maria; Zographos, Spyros E; Lederer, Carsten W; Kyriakides, Theodore; Pfaffl, Michael W; Santama, Niovi

    2007-06-01

    The molecular mechanisms underlying the selective neurodegeneration of motor neurons in amyotrophic lateral sclerosis (ALS) are inadequately understood. Recent breakthroughs have implicated impaired axonal transport, mediated by molecular motors, as a key element for disease onset and progression. The current work identifies the expression of 15 kinesin-like motors in healthy human motor cortex, including three novel isoforms. Our comprehensive quantitative mRNA analysis in control and sporadic ALS (SALS) motor cortex specimens detects SALS-specific down-regulation of KIF1Bbeta and novel KIF3Abeta, two isoforms we show to be enriched in the brain, and also of SOD1, a key enzyme linked to familial ALS. This is accompanied by a marked reduction of KIF3Abeta protein levels. In the motor cortex KIF3Abeta localizes in cholinergic neurons, including upper motor neurons. No mutations causing splicing defects or altering protein-coding sequences were identified in the genes of the three proteins. The present study implicates two motor proteins as possible candidates in SALS pathology. PMID:17418584

  10. Measurements of evoked electroencephalograph by transcranial magnetic stimulation applied to motor cortex and posterior parietal cortex

    Science.gov (United States)

    Iwahashi, Masakuni; Koyama, Yohei; Hyodo, Akira; Hayami, Takehito; Ueno, Shoogo; Iramina, Keiji

    2009-04-01

    To investigate the functional connectivity, the evoked potentials by stimulating at the motor cortex, the posterior parietal cortex, and the cerebellum by transcranial magnetic stimulation (TMS) were measured. It is difficult to measure the evoked electroencephalograph (EEG) by the magnetic stimulation because of the large artifact induced by the magnetic pulse. We used an EEG measurement system with sample-and-hold circuit and an independent component analysis to eliminate the electromagnetic interaction emitted from TMS. It was possible to measure EEG signals from all electrodes over the head within 10 ms after applying the TMS. When the motor area was stimulated by TMS, the spread of evoked electrical activity to the contralateral hemisphere was observed at 20 ms after stimulation. However, when the posterior parietal cortex was stimulated, the evoked electrical activity to the contralateral hemisphere was not observed. When the cerebellum was stimulated, the cortical activity propagated from the stimulated point to the frontal area and the contralateral hemisphere at around 20 ms after stimulation. These results suggest that the motor area has a strong interhemispheric connection and the posterior parietal cortex has no interhemispheric connection.

  11. Intracortical inhibition of the motor cortex is normal in chorea

    OpenAIRE

    HANAJIMA, R; Ugawa, Y; Y. Terao; Furubayashi, T.; Machii, K; Shiio, Y.; H. Enomoto; Uesugi, H.; Mochizuki, H.; Kanazawa, I

    1999-01-01

    Intracortical inhibition of the motor cortex was investigated using a paired pulse magnetic stimulation method in 14 patients with chorea caused by various aetiologies (six patients with Huntington's disease, one with chorea acanthocytosis, a patient with systemic lupus erythematosus with a vascular lesion in the caudate, three with senile chorea and three with chorea of unknown aetiology). The time course and amount of inhibition was the same in the patients as in normal su...

  12. Heterogeneous neural coding of corrective movements in motor cortex

    Science.gov (United States)

    Dickey, Adam S.; Amit, Yali; Hatsopoulos, Nicholas G.

    2013-01-01

    During a reach, neural activity recorded from motor cortex is typically thought to linearly encode the observed movement. However, it has also been reported that during a double-step reaching paradigm, neural coding of the original movement is replaced by that of the corrective movement. Here, we use neural data recorded from multi-electrode arrays implanted in the motor and premotor cortices of rhesus macaques to directly compare these two hypotheses. We show that while a majority of neurons display linear encoding of movement during a double-step, a minority display a dramatic drop in firing rate that is predicted by the replacement hypothesis. Neural activity in the subpopulation showing replacement is more likely to lag the observed movement, and may therefore be involved in the monitoring of the sensory consequences of a motor command. PMID:23576955

  13. Neurochemical correlates of. gamma. -aminobutyrate (GABA) inhibition in cat visual cortex

    Energy Technology Data Exchange (ETDEWEB)

    Balcar, V.J.; Dreher, B. (Univ. of Sydney (Australia))

    1990-01-01

    High affinity binding of ({sup 3}H){gamma}-aminobutyric acid (GABA) to neuronal membranes from different parts of cat visual cortex was tested for sensitivity to GABA{sub A} agonists isoguvacine and THIP, GABA{sub A} antagonist SR95531 and GABA{sub B} agonist baclofen. Some of the GABA{sub A}-binding sites were found to have a very low affinity for THIP, suggesting the presence and, possibly, uneven distribution of non-synaptic GABA{sub A} receptors in cat visual cortex. There were no differences in K{sub m} and V{sub max} values of high affinity uptake of GABA and in the potency of K{sup +}-stimulated release of GABA, between primary and association cortices. Consequently, the present results indicate that despite the anatomical and physiological differences between the primary and association feline visual cortices the neurochemical characteristics of GABAergic inhibition are very similar in the two regions.

  14. Neurochemical correlates of γ-aminobutyrate (GABA) inhibition in cat visual cortex

    International Nuclear Information System (INIS)

    High affinity binding of [3H]γ-aminobutyric acid (GABA) to neuronal membranes from different parts of cat visual cortex was tested for sensitivity to GABAA agonists isoguvacine and THIP, GABAA antagonist SR95531 and GABAB agonist baclofen. Some of the GABAA-binding sites were found to have a very low affinity for THIP, suggesting the presence and, possibly, uneven distribution of non-synaptic GABAA receptors in cat visual cortex. There were no differences in Km and Vmax values of high affinity uptake of GABA and in the potency of K+-stimulated release of GABA, between primary and association cortices. Consequently, the present results indicate that despite the anatomical and physiological differences between the primary and association feline visual cortices the neurochemical characteristics of GABAergic inhibition are very similar in the two regions

  15. Contributions of the cerebellum and the motor cortex to acquisition and retention of motor memories

    OpenAIRE

    Herzfeld, David J.; Pastor, Damien; Haith, Adrian M.; Rossetti, Yves; Shadmehr, Reza; O’Shea, Jacinta

    2014-01-01

    We investigated the contributions of the cerebellum and the motor cortex (M1) to acquisition and retention of human motor memories in a force field reaching task. We found that anodal transcranial direct current stimulation (tDCS) of the cerebellum, a technique that is thought to increase neuronal excitability, increased the ability to learn from error and form an internal model of the field, while cathodal cerebellar stimulation reduced this error-dependent learning. In addition, cathodal ce...

  16. Directional tunings independent of orientation in the primary visual cortex of the cat

    Institute of Scientific and Technical Information of China (English)

    陈垚; 李兵; 李宝旺; 刁云程

    2001-01-01

    A family of moving ‘random-line' patterns was developed and used to study the directional tuning of 91 single units in cat primary visual cortex (V1). The results suggest that, in addition to the well-known orientation-dependent mechanism, there is also some kind of orientation-independent mechanism underlying the direction selectivity. The directional tuning of the neurons varies in accordance with the increase of orientation or non-orientation element in the stimulus.

  17. Columnar Architecture Sculpted by GABA Circuits in Developing Cat Visual Cortex

    OpenAIRE

    Hensch, Takao K.; Stryker, Michael P.

    2004-01-01

    The mammalian visual cortex is organized into columns. Here, we examine cortical influences upon developing visual afferents in the cat by altering intrinsic γ-aminobutyric acid (GABA)–mediated inhibition with benzodiazepines. Local enhancement by agonist (diazepam) infusion did not perturb visual responsiveness, but did widen column spacing. An inverse agonist (DMCM) produced the opposite effect. Thus, intracortical inhibitory circuits shape the geometry of incoming thalamic arbors, suggesti...

  18. Visual responses in adult cat visual cortex depend on N-methyl-D-aspartate receptors.

    OpenAIRE

    Miller, K. D.; Chapman, B; Stryker, M.P.

    1989-01-01

    We have investigated the role of the N-methyl-D-aspartate (NMDA) receptor, a subtype of glutamate receptor, in the responses of cells in adult cat visual cortex. After intracortical infusion of the NMDA receptor antagonist DL-2-amino-5-phosphonovalerate (DL-APV) for one day, iontophoretic responses to NMDA, to kainate, and to quisqualate revealed a receptor blockade specific to NMDA receptors and extending several millimeters from the cannula. In this region, neuronal responses to visual stim...

  19. Motor Cortex Activity During Functional Motor Skills: An fNIRS Study.

    Science.gov (United States)

    Nishiyori, Ryota; Bisconti, Silvia; Ulrich, Beverly

    2016-01-01

    Assessments of brain activity during motor task performance have been limited to fine motor movements due to technological constraints presented by traditional neuroimaging techniques, such as functional magnetic resonance imaging. Functional near-infrared spectroscopy (fNIRS) offers a promising method by which to overcome these constraints and investigate motor performance of functional motor tasks. The current study used fNIRS to quantify hemodynamic responses within the primary motor cortex in twelve healthy adults as they performed unimanual right, unimanual left, and bimanual reaching, and stepping in place. Results revealed that during both unimanual reaching tasks, the contralateral hemisphere showed significant activation in channels located approximately 3 cm medial to the C3 (for right-hand reach) and C4 (for left-hand reach) landmarks. Bimanual reaching and stepping showed activation in similar channels, which were located bilaterally across the primary motor cortex. The medial channels, surrounding Cz, showed significantly higher activations during stepping when compared to bimanual reaching. Our results extend the viability of fNIRS to study motor function and build a foundation for future investigation of motor development in infants during nascent functional behaviors and monitor how they may change with age or practice. PMID:26243304

  20. Kick with the finger: symbolic actions shape motor cortex excitability.

    Science.gov (United States)

    Betti, Sonia; Castiello, Umberto; Sartori, Luisa

    2015-11-01

    A large body of research indicates that observing actions made by others is associated with corresponding motor facilitation of the observer's corticospinal system. However, it is still controversial whether this matching mechanism strictly reflects the kinematics of the observed action or its meaning. To test this issue, motor evoked potentials induced by single-pulse transcranial magnetic stimulation were recorded from hand and leg muscles while participants observed a symbolic action carried out with the index finger, but classically performed with the leg (i.e., a soccer penalty kick). A control condition in which participants observed a similar (but not symbolic) hand movement was also included. Results showed that motor facilitation occurs both in the observer's hand (first dorsal interosseous) and leg (quadriceps femoris) muscles. The present study provides evidence that both the kinematics and the symbolic value of an observed action are able to modulate motor cortex excitability. The human motor system is thus not only involved in mirroring observed actions but is also finely tuned to their symbolic value. PMID:26354677

  1. Therapy induces widespread reorganization of motor cortex after complete spinal transection that supports motor recovery.

    Science.gov (United States)

    Ganzer, Patrick D; Manohar, Anitha; Shumsky, Jed S; Moxon, Karen A

    2016-05-01

    Reorganization of the somatosensory system and its relationship to functional recovery after spinal cord injury (SCI) has been well studied. However, little is known about the impact of SCI on organization of the motor system. Recent studies suggest that step-training paradigms in combination with spinal stimulation, either electrically or through pharmacology, are more effective than step training alone at inducing recovery and that reorganization of descending corticospinal circuits is necessary. However, simpler, passive exercise combined with pharmacotherapy has also shown functional improvement after SCI and reorganization of, at least, the sensory cortex. In this study we assessed the effect of passive exercise and serotonergic (5-HT) pharmacological therapies on behavioral recovery and organization of the motor cortex. We compared the effects of passive hindlimb bike exercise to bike exercise combined with daily injections of 5-HT agonists in a rat model of complete mid-thoracic transection. 5-HT pharmacotherapy combined with bike exercise allowed the animals to achieve unassisted weight support in the open field. This combination of therapies also produced extensive expansion of the axial trunk motor cortex into the deafferented hindlimb motor cortex and, surprisingly, reorganization within the caudal and even the rostral forelimb motor cortex areas. The extent of the axial trunk expansion was correlated to improvement in behavioral recovery of hindlimbs during open field locomotion, including weight support. From a translational perspective, these data suggest a rationale for developing and optimizing cost-effective, non-invasive, pharmacological and passive exercise regimes to promote plasticity that supports restoration of movement after spinal cord injury. PMID:26826448

  2. Peripheral nerve injury induces glial activation in primary motor cortex

    Directory of Open Access Journals (Sweden)

    Julieta Troncoso

    2015-02-01

    Full Text Available Preliminary evidence suggests that peripheral facial nerve injuries are associated with sensorimotor cortex reorganization. We have characterized facial nerve lesion-induced structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with glial cell density using a rodent facial paralysis model. First, we used adult transgenic mice expressing green fluorescent protein in microglia and yellow fluorescent protein in pyramidal neurons which were subjected to either unilateral lesion of the facial nerve or sham surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1. It was found that facial nerve lesion induced long-lasting changes in dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Pyramidal cells’ dendritic arborization underwent overall shrinkage and transient spine pruning. Moreover, microglial cell density surrounding vM1 layer 5 pyramidal neurons was significantly increased with morphological bias towards the activated phenotype. Additionally, we induced facial nerve lesion in Wistar rats to evaluate the degree and extension of facial nerve lesion-induced reorganization processes in central nervous system using neuronal and glial markers. Immunoreactivity to NeuN (neuronal nuclei antigen, GAP-43 (growth-associated protein 43, GFAP (glial fibrillary acidic protein, and Iba 1 (Ionized calcium binding adaptor molecule 1 were evaluated 1, 3, 7, 14, 28 and 35 days after either unilateral facial nerve lesion or sham surgery. Patches of decreased NeuN immunoreactivity were found bilaterally in vM1 as well as in primary somatosensory cortex (CxS1. Significantly increased GAP-43 immunoreactivity was found bilaterally after the lesion in hippocampus, striatum, and sensorimotor cortex. One day after lesion GFAP immunoreactivity increased bilaterally in hippocampus, subcortical white

  3. Population response characteristics of intrinsic signals in the cat somatosensory cortex following canine mechanical stimulation.

    Science.gov (United States)

    Tao, Jianxiang; Wang, Jian; Li, Zhong; Meng, Jianjun; Yu, Hongbo

    2016-08-01

    Intrinsic signal optical imaging has been widely used to measure functional maps in various sensory cortices due to better spatial resolution and sensitivity for detecting cortical neuroplasticity. However, application of this technique in dentistry has not been reported. In this study, intrinsic signal optical imaging was used to investigate mechanically driven responses in the cat somatosensory cortex, when punctate mechanical stimuli were applied to maxillary canines. The global signal and its spatial organization pattern were obtained. Global signal strength gradually increased with stimulus strength. There was no significant difference in response strength between contralateral and ipsilateral mechanical stimulation. A slightly greater response was recorded in the sigmoidal gyrus than in the coronal gyrus. The cat somatosensory cortex activated by sensory inputs from mechanical stimulation of canines lacks both topographical and functional organization. It is not organized into columns that represent sensory input from each tooth or direction of stimulation. These results demonstrate that intrinsic signal optical imaging is a valid tool for investigating neural responses and neuroplasticity in the somatosensory cortex that represents teeth. PMID:27163378

  4. Reduced motor cortex activity during movement preparation following a period of motor skill practice.

    Directory of Open Access Journals (Sweden)

    David J Wright

    Full Text Available 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.

  5. Rat whisker motor cortex is subdivided into sensory-input and motor-output areas

    OpenAIRE

    Alloway, Kevin D.

    2013-01-01

    Rodent whisking is an exploratory behavior that can be modified by sensory feedback. Consistent with this, many whisker-sensitive cortical regions project to agranular motor (MI) cortex, but the relative topography of these afferent projections has not been established. Intracranial microstimulation (ICMS) evokes whisker movements that are used to map the functional organization of MI, but no study has compared the whisker-related inputs to MI with the ICMS sites that evoke whisker movements....

  6. A systematic review of non-motor rTMS induced motor cortex plasticity

    OpenAIRE

    Nordmann, Grégory; Azorina, Valeriya; Langguth, Berthold; Schecklmann, Martin

    2015-01-01

    Motor cortex excitability can be measured by single- and paired-pulse transcranial magnetic stimulation (TMS). Repetitive transcranial magnetic stimulation (rTMS) can induce neuroplastic effects in stimulated and in functionally connected cortical regions. Due to its ability to non-invasively modulate cortical activity, rTMS has been investigated for the treatment of various neurological and psychiatric disorders. However, such studies revealed a high variability of both clinical and neuronal...

  7. Motor cortex electric stimulation for the treatment of neuropathic pain

    Directory of Open Access Journals (Sweden)

    Walter J. Fagundes-Pereyra

    2010-12-01

    Full Text Available OBJECTIVE: Motor cortex stimulation (MCS is considered to be an effective treatment for chronic neuropathic pain. The aim of the present study was to assess the efficacy of MCS for treating neuropathic pain. METHOD: 27 patients with chronic neuropathic pain were operated. Electrodes were implanted with the use of an stereotactic frame. Electrophysiological evaluations (motor stimulation and somatosensory evoked potentials were performed, with guidance by means of three-dimensional reconstruction of magnetic resonance images of the brain. 10 patients (37% presented central neuropathic pain (post-stroke pain and 17 others (63% presented peripheral neuropathic pain (brachial plexus avulsion, phantom limb pain or trigeminal pain. RESULTS: In 15 patients (57.7% the pain relief was 50% or more; while in ten patients (38.5%, more than 60% of the original pain was relieved. No differences were found in relation to central and peripheral neuropathic pain (p=0.90, pain location (p=0.81, presence of motor deficit (p=0.28 and pain duration (p=0.72. No major complications were observed. CONCLUSION: MCS was efficient for treating patients presenting chronic central or peripheral neuropathic pain.

  8. Numbers of specific types of neuron in layer IVab of cat striate cortex.

    OpenAIRE

    Solnick, B; Davis, T L; Sterling, P

    1984-01-01

    Layer IVab of the visual cortex (area 17) of the cat contains about 51,400 neurons per mm3, including about 400-1200 per mm3 of each of three categories of neuron believed from previous work to represent discrete types. Each type forms about 0.5-1.5% of all the IVab neurons, which suggests that the total number of types in this layer might be much greater than previously supposed, perhaps as many as 50 or more. From their densities and estimates of their dendritic fields, we calculate that ea...

  9. The Basal Forebrain and Motor Cortex Provide Convergent yet Distinct Movement-Related Inputs to the Auditory Cortex.

    Science.gov (United States)

    Nelson, Anders; Mooney, Richard

    2016-05-01

    Cholinergic inputs to the auditory cortex from the basal forebrain (BF) are important to auditory processing and plasticity, but little is known about the organization of these synapses onto different auditory cortical neuron types, how they influence auditory responsiveness, and their activity patterns during various behaviors. Using intersectional tracing, optogenetic circuit mapping, and in vivo calcium imaging, we found that cholinergic axons arising from the caudal BF target major excitatory and inhibitory auditory cortical cell types, rapidly modulate auditory cortical tuning, and display fast movement-related activity. Furthermore, the BF and the motor cortex-another source of movement-related activity-provide convergent input onto some of the same auditory cortical neurons. Cholinergic and motor cortical afferents to the auditory cortex display distinct activity patterns and presynaptic partners, indicating that the auditory cortex integrates bottom-up cholinergic signals related to ongoing movements and arousal with top-down information concerning impending movements and motor planning. PMID:27112494

  10. Continuous theta-burst stimulation of the primary motor cortex in essential tremor

    DEFF Research Database (Denmark)

    Hellriegel, Helge; Schulz, Eva M; Siebner, Hartwig R; Deuschl, Günther; Raethjen, Jan H

    2012-01-01

    We investigated whether essential tremor (ET) can be altered by suppressing the corticospinal excitability in the primary motor cortex (M1) with transcranial magnetic stimulation.......We investigated whether essential tremor (ET) can be altered by suppressing the corticospinal excitability in the primary motor cortex (M1) with transcranial magnetic stimulation....

  11. Competing Neural Ensembles in Motor Cortex Gate Goal-Directed Motor Output.

    Science.gov (United States)

    Zagha, Edward; Ge, Xinxin; McCormick, David A

    2015-11-01

    Unit recordings in behaving animals have revealed the transformation of sensory to motor representations in cortical neurons. However, we still lack basic insights into the mechanisms by which neurons interact to generate such transformations. Here, we study cortical circuits related to behavioral control in mice engaged in a sensory detection task. We recorded neural activity using extracellular and intracellular techniques and analyzed the task-related neural dynamics to reveal underlying circuit processes. Within motor cortex, we find two populations of neurons that have opposing spiking patterns in anticipation of movement. From correlation analyses and circuit modeling, we suggest that these dynamics reflect neural ensembles engaged in a competition. Furthermore, we demonstrate how this competitive circuit may convert a transient, sensory stimulus into a motor command. Together, these data reveal cellular and circuit processes underlying behavioral control and establish an essential framework for future studies linking cellular activity to behavior. PMID:26593093

  12. Interactions between Pain and the Motor Cortex: Insights from Research on Phantom Limb Pain and Complex Regional Pain Syndrome

    OpenAIRE

    Mercier, Catherine; Léonard, Guillaume

    2011-01-01

    Purpose: Pain is a significantly disabling problem that often interacts with other deficits during the rehabilitation process. The aim of this paper is to review evidence of interactions between pain and the motor cortex in order to attempt to answer the following questions: (1) Does acute pain interfere with motor-cortex activity? (2) Does chronic pain interfere with motor-cortex activity, and, conversely, does motor-cortex plasticity contribute to chronic pain? (3) Can the induction of moto...

  13. Motor Cortex Stimulation for Pain Relief: Do Corollary Discharges Play a Role?

    Science.gov (United States)

    Brasil-Neto, Joaquim P.

    2016-01-01

    Both invasive and non-invasive motor cortex stimulation techniques have been successfully employed in the treatment of chronic pain, but the precise mechanism of action of such treatments is not fully understood. It has been hypothesized that a mismatch of normal interaction between motor intention and sensory feedback may result in central pain. Sensory feedback may come from peripheral nerves, vision and also from corollary discharges originating from the motor cortex itself. Therefore, a possible mechanism of action of motor cortex stimulation might be corollary discharge reinforcement, which could counterbalance sensory feedback deficiency. In other instances, primary deficiency in the production of corollary discharges by the motor cortex might be the culprit and stimulation of cortical motor areas might then be beneficial by enhancing production of such discharges. Here we review evidence for a possible role of motor cortex corollary discharges upon both the pathophysiology and the response to motor cortex stimulation of different types of chronic pain. We further suggest that the right dorsolateral prefrontal cortex (DLPC), thought to constantly monitor incongruity between corollary discharges, vision and proprioception, might be an interesting target for non-invasive neuromodulation in cases of chronic neuropathic pain.

  14. Rat whisker motor cortex is subdivided into sensory-input and motor-output areas

    Directory of Open Access Journals (Sweden)

    Jared B Smith

    2013-01-01

    Full Text Available Rodent whisking is an exploratory behavior that can be modified by sensory feedback. Consistent with this, many whisker-sensitive cortical regions project to agranular motor (MI cortex, but the relative topography of these afferent projections has not been established. Intracranial microstimulation (ICMS evokes whisker movements that are used to map the functional organization of MI, but no study has compared the whisker-related inputs to MI with the ICMS sites that evoke whisker movements. To elucidate this relationship, anterograde tracers were placed in posterior parietal cortex (PPC and in the primary (SI and secondary (SII somatosensory cortical areas so that their labeled projections to MI could be analyzed with respect to ICMS sites that evoke whisker movements. Projections from SI and SII terminate in a narrow zone that marks the transition between the medial (AGm and lateral agranular (AGl cortical areas, but PPC projects more medially and terminates in AGm proper. Paired recordings of MI neurons indicate that the region between AGm and AGl is highly responsive to whisker deflections, but neurons in AGm display negligible responses to whisker stimulation. By contrast, AGm microstimulation is more effective in evoking whisker movements than microstimulation of the transitional region between AGm and AGl. The AGm region was also found to contain a larger concentration of corticotectal neurons, which could convey whisker-related information to the facial nucleus. These results indicate that rat whisker motor cortex is comprised of at least two functionally distinct subregions: a sensory processing zone in the transitional region between AGm and AGl, and a motor output region located more medially in AGm proper.

  15. Motor cortex changes after amputation are modulated by phantom limb motor control rather than pain

    DEFF Research Database (Denmark)

    Raffin, Estelle E.; Pascal, Giraux,; Karen, Reilly,; Nathalie, Richard,

    retains a residual M1-c activity when amputees perform phantom limb movements (4-5). Except a correlation between phantom limb pain and M1-c expansion of the face (2-3), the relationship between the ability to voluntary move the phantom hand, the level of phantom limb pain, the degree of M1-c......Amputation of a limb induces reorganization within the contralateral primary motor cortex (M1-c) (1-3). In the case of hand amputation, M1-c areas evoking movements in the face and the remaining part of the upper-limb expand toward the hand area. Despite this expansion, the amputated hand still...

  16. Functional Magnetic Resonance Imaging of Motor Cortex: Hemispheric Asymmetry and Handedness

    Science.gov (United States)

    Kim, Seong-Gi; Ashe, James; Hendrich, Kristy; Ellermann, Jutta M.; Merkle, Hellmut; Ugurbil, Kamil; Georgopoulos, Apostolos P.

    1993-07-01

    A hemispheric asymmetry in the functional activation of the human motor cortex during contralateral (C) and ipsilateral (I) finger movements, especially in right-handed subjects, was documented with nuclear magnetic resonance imaging at high field strength (4 tesla). Whereas the right motor cortex was activated mostly during contralateral finger movements in both right-handed (C/I mean area of activation = 36.8) and left-handed (C/I = 29.9) subjects, the left motor cortex was activated substantially during ipsilateral movements in left-handed subjects (C/I = 5.4) and even more so in right-handed subjects (C/I = 1.3).

  17. Increased resting state connectivity between ipsilesional motor cortex and contralesional premotor cortex after transcranial direct current stimulation with physical therapy.

    Science.gov (United States)

    Chen, Joyce L; Schlaug, Gottfried

    2016-01-01

    Non-invasive stimulation of the brain using transcranial direct current stimulation (tDCS) during motor rehabilitation can improve the recovery of movements in individuals with stroke. However, the neural substrates that underlie the clinical improvements are not well understood. In this proof-of-principle open-label pilot study, five individuals with stroke received 10 sessions of tDCS while undergoing usual care physical/occupational therapy for the arm and hand. Motor impairment as indexed by the Upper Extremity Fugl Meyer assessment was significantly reduced after the intervention. Resting state fMRI connectivity increased between ipsilesional motor cortex and contralesional premotor cortex after the intervention. These findings provide preliminary evidence that the neural underpinnings of tDCS coupled with rehabilitation exercises, may be mediated by interactions between motor and premotor cortex. The latter, of which has been shown to play an important role in the recovery of movements post-stroke. Our data suggest premotor cortex could be tested as a target region for non-invasive brain-stimulation to enhance connectivity between regions that might be beneficial for stroke motor recovery. PMID:26980052

  18. Protein Synthesis Inhibition in the Peri-Infarct Cortex Slows Motor Recovery in Rats

    Science.gov (United States)

    Schubring-Giese, Maximilian; Leemburg, Susan; Luft, Andreas Rüdiger; Hosp, Jonas Aurel

    2016-01-01

    Neuroplasticity and reorganization of brain motor networks are thought to enable recovery of motor function after ischemic stroke. Especially in the cortex surrounding the ischemic scar (i.e., peri-infarct cortex), evidence for lasting reorganization has been found at the level of neurons and networks. This reorganization depends on expression of specific genes and subsequent protein synthesis. To test the functional relevance of the peri-infarct cortex for recovery we assessed the effect of protein synthesis inhibition within this region after experimental stroke. Long-Evans rats were trained to perform a skilled-reaching task (SRT) until they reached plateau performance. A photothrombotic stroke was induced in the forelimb representation of the primary motor cortex (M1) contralateral to the trained paw. The SRT was re-trained after stroke while the protein synthesis inhibitor anisomycin (ANI) or saline were injected into the peri-infarct cortex through implanted cannulas. ANI injections reduced protein synthesis within the peri-infarct cortex by 69% and significantly impaired recovery of reaching performance through re-training. Improvement of motor performance within a single training session remained intact, while improvement between training sessions was impaired. ANI injections did not affect infarct size. Thus, protein synthesis inhibition within the peri-infarct cortex impairs recovery of motor deficits after ischemic stroke by interfering with consolidation of motor memory between training sessions but not short-term improvements within one session. PMID:27314672

  19. Spectrotemporal receptive fields during spindling and non-spindling epochs in cat primary auditory cortex.

    Science.gov (United States)

    Britvina, T; Eggermont, J J

    2008-07-17

    It was often thought that synchronized rhythmic epochs of spindle waves disconnect thalamo-cortical system from incoming sensory signals. The present study addresses this issue by simultaneous extracellular action potential and local field potential (LFP) recordings from primary auditory cortex of ketamine-anesthetized cats during spindling activity. We compared cortical spectrotemporal receptive fields (STRF) obtained during spindling and non-spindling epochs. The basic spectro-temporal parameters of "spindling" and "non-spindling" STRFs were similar. However, the peak-firing rate at the best frequency was significantly enhanced during spindling epochs. This enhancement was mainly caused by the increased probability of a stimulus to evoke spikes (effectiveness of stimuli) during spindling as compared with non-spindling epochs. Augmented LFPs associated with effective stimuli and increased single-unit pair correlations during spindling epochs suggested higher synchrony of thalamo-cortical inputs during spindling that resulted in increased effectiveness of stimuli presented during spindling activity. The neuronal firing rate, both stimulus-driven and spontaneous, was higher during spindling as compared with non-spindling epochs. Overall, our results suggests that thalamic cells during spindling respond to incoming stimuli-related inputs and, moreover, cause more powerful stimulus-related or spontaneous activation of the cortex. PMID:18515012

  20. Effect of Contrast on Visual Spatial Summation in Different Cell Categories in Cat Primary Visual Cortex.

    Directory of Open Access Journals (Sweden)

    Ke Chen

    Full Text Available Multiple cell classes have been found in the primary visual cortex, but the relationship between cell types and spatial summation has seldom been studied. Parvalbumin-expressing inhibitory interneurons can be distinguished from pyramidal neurons based on their briefer action potential durations. In this study, we classified V1 cells into fast-spiking units (FSUs and regular-spiking units (RSUs and then examined spatial summation at high and low contrast. Our results revealed that the excitatory classical receptive field and the suppressive non-classical receptive field expanded at low contrast for both FSUs and RSUs, but the expansion was more marked for the RSUs than for the FSUs. For most V1 neurons, surround suppression varied as the contrast changed from high to low. However, FSUs exhibited no significant difference in the strength of suppression between high and low contrast, although the overall suppression decreased significantly at low contrast for the RSUs. Our results suggest that the modulation of spatial summation by stimulus contrast differs across populations of neurons in the cat primary visual cortex.

  1. Cross-correlations between three units in cat primary auditory cortex.

    Science.gov (United States)

    Eggermont, Jos J; Munguia, Raymundo; Shaw, Gregory

    2013-10-01

    Here we use a modification of the Joint-Peri-Stimulus-Time histogram (JPSTH) to investigate triple correlations between cat auditory cortex neurons. The modified procedure allowed the decomposition of the xy-pair correlation into a part that is due to the correlation of the x and y units with the trigger unit, and a remaining 'pair correlation'. We analyzed 16 sets of 15-minute duration stationary spontaneous recordings in primary auditory cortex (AI) with between 11 and 14 electrodes from 2 arrays of 8 electrodes each that provided spontaneous firing rates above 0.22 sp/s and for which reliable frequency-tuning curves could be obtained and the characteristic frequency (CF) was estimated. Thus we evaluated 11,282 conditional cross-correlation functions. The predictor for the conditional cross-correlation, calculated on the assumption that the trigger unit had no effect on the xy-pair correlation but using the same fraction of xy spikes, was equal to the conventional pair-wise correlation function between units xy. The conditional correlation of the xy-pair due to correlation of the x and/or y unit with the trigger unit decreased with the geometric mean distance of the xy pair to the trigger unit, but was independent of the pair cross-correlation coefficient. The conditional pair correlation coefficient was estimated at 78% of the measured pair correlation coefficient. Assuming a geometric decreasing effect of activities of units on other electrodes on the conditional correlation, we estimated the potential contribution of a large number of contributing units on the measured pair correlation at 35-50 of that correlation. This suggests that conventionally measured pair correlations in auditory cortex under ketamine anesthesia overestimate the 'true pair correlation', likely resulting from massive common input, by potentially up to a factor 2. PMID:23933479

  2. Hippocampal EEG and motor activity in the cat: The role of eye movements and body acceleration

    NARCIS (Netherlands)

    Kamp, A.; Arnolds, D.E.A.T.; Lopes da Silva, F.H.; Boeijinga, P.; Aitink, W.

    1984-01-01

    In cat the relation between various behaviours and the spectral properties of the hippocampal EEG was investigated. Both EEG and behaviour were quantified and results were evaluated statistically. Significant relationships were found between the properties of the hippocampal EEG and motor acts (walk

  3. Persistent abnormalities of membrane excitability in regenerated mature motor axons in cat

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Krarup, Christian

    2004-01-01

    The purpose of our study was to assess by threshold tracking internodal and nodal membrane excitability during the maturation process after tibial nerve crush in cat. Various excitability indices (EI) were computed non-invasively by comparing the threshold of a submaximal compound motor potential...

  4. Developmental changes in motor cortex activity as infants develop functional motor skills.

    Science.gov (United States)

    Nishiyori, Ryota; Bisconti, Silvia; Meehan, Sean K; Ulrich, Beverly D

    2016-09-01

    Despite extensive research examining overt behavioral changes of motor skills in infants, the neural basis underlying the emergence of functional motor control has yet to be determined. We used functional near-infrared spectroscopy (fNIRS) to record hemodynamic activity of the primary motor cortex (M1) from 22 infants (11 six month-olds, 11 twelve month-olds) as they reached for an object, and stepped while supported over a treadmill. Based on the developmental systems framework, we hypothesized that as infants increased goal-directed experience, neural activity shifts from a diffused to focal pattern. Results showed that for reaching, younger infants showed diffuse areas of M1 activity that became focused by 12 months. For elicited stepping, younger infants produced much less M1 activity which shifted to diffuse activity by 12 months. Thus, the data suggest that as infants gain goal-directed experience, M1 activity emerges, initially showing a diffuse area of activity, becoming refined as the behavior stabilizes. Our data begin to document the cortical activity underlying early functional skill acquisition. PMID:27096281

  5. Methylmercury intoxication and histochemical demonstration of NADPH-diaphorase activity in the striate cortex of adult cats

    OpenAIRE

    OLIVEIRA, R. B.; W. Gomes-Leal; J.L.M. do-Nascimento; C.W. Picanço-Diniz

    1998-01-01

    The effects of methylmercury (MeHg) on histochemical demonstration of the NADPH-diaphorase (NADPH-d) activity in the striate cortex were studied in 4 adult cats. Two animals were used as control. The contaminated animals received 50 ml milk containing 0.42 µg MeHg and 100 g fish containing 0.03 µg MeHg daily for 2 months. The level of MeHg in area 17 of intoxicated animals was 3.2 µg/g wet weight brain tissue. Two cats were perfused 24 h after the last dose (group 1) and the other animals wer...

  6. The use of a T-maze to measure cognitive-motor function in cats (Felis catus)

    OpenAIRE

    Sherman, Barbara L.; Gruen, Margaret E.; Meeker, Rick B.; Milgram, Bill; DiRivera, Christina; Thomson, Andrea; Clary, Gillian; Hudson, Lola

    2013-01-01

    Few tests have been developed to test the cognitive and motor capabilities of domestic cats, in spite of the suitability of cats for specific studies of neuroanatomy, infectious diseases, development, aging, and behavior. The present study evaluated a T-maze apparatus as a sensitive and reliable measure of cognition and motor function of cats. Eighteen purpose-bred, specific-pathogen-free, male, neutered domestic shorthair cats (Felis catus), 1-2 years of age, were trained and tested to a T-m...

  7. The motor cortex drives the muscles during walking in human subjects

    DEFF Research Database (Denmark)

    Petersen, Tue Hvass; Willerslev-Olsen, Maria; Conway, B A; Nielsen, Jens Bo

    2012-01-01

    Indirect evidence that the motor cortex and the corticospinal tract contribute to the control of walking in human subjects has been provided in previous studies. In the present study we used coherence analysis of the coupling between EEG and EMG from active leg muscles during human walking to...... address if activity arising in the motor cortex contributes to the muscle activity during gait. Nine healthy human subjects walked on a treadmill at a speed of 3.5–4 km h(-1). Seven of the subjects in addition walked at a speed of 1 km h(-1). Significant coupling between EEG recordings over the leg motor...

  8. Prefrontal Control over Motor Cortex Cycles at Beta Frequency during Movement Inhibition

    OpenAIRE

    Picazio, Silvia; Veniero, Domenica; Ponzo, Viviana; Caltagirone, Carlo; Gross, Joachim; Thut, Gregor; Koch, Giacomo

    2014-01-01

    A fully adapted behavior requires maximum efficiency to inhibit processes in the motor domain [ 1 ]. Although a number of cortical and subcortical brain regions have been implicated, converging evidence suggests that activation of right inferior frontal gyrus (r-IFG) and right presupplementary motor area (r-preSMA) is crucial for successful response inhibition [ 2, 3 ]. However, it is still unknown how these prefrontal areas convey the necessary signal to the primary motor cortex (M1), the co...

  9. Response of SII cortex to ipsilateral, contralateral and bilateral flutter stimulation in the cat

    Directory of Open Access Journals (Sweden)

    Favorov Oleg

    2005-02-01

    Full Text Available Abstract Background A distinctive property of SII is that it is the first cortical stage of the somatosensory projection pathway that integrates information arising from both sides of the body. However, there is very little known about how inputs across the body mid-line are processed within SII. Results Optical intrinsic signal imaging was used to evaluate the response of primary somatosensory cortex (SI and SII in the same hemisphere to 25 Hz sinusoidal vertical skin displacement stimulation ("skin flutter" applied contralaterally, ipsilaterally, and bilaterally to the central pads of the forepaws. A localized increase in absorbance in both SI and SII was evoked by both contralateral and bilateral flutter stimulation. Ipsilateral flutter stimulation evoked a localized increase in absorbance in SII, but not in SI. The SII region that responded with an increase in absorbance to ipsilateral stimulation was posterior to the region in which absorbance increased maximally in response to stimulation of the contralateral central pad. Additionally, in the posterior SII region that responded maximally to ipsilateral stimulation of the central pad, bilateral central pad stimulation approximated a linear summation of the SII responses to independent stimulation of the contralateral and ipsilateral central pads. Conversely, in anterior SII (the region that responded maximally to contralateral stimulation, bilateral stimulation was consistently less than the response evoked from the contralateral central pad. Conclusions The results indicate that two regions located at neighboring, but distinctly different A-P levels of the anterior ectosylvian gyrus process input from opposite sides of the body midline in very different ways. The results suggest that the SII cortex, in the cat, can be subdivided into at least two functionally distinct regions and that these functionally distinct regions demonstrate a laterality preference within SII.

  10. [Treatment of central and neuropathic facial pain by chronic stimulation of the motor cortex: value of neuronavigation guidance systems for the localization of the motor cortex].

    Science.gov (United States)

    Nguyen, J P; Lefaucheur, J P; Le Guerinel, C; Fontaine, D; Nakano, N; Sakka, L; Eizenbaum, J F; Pollin, B; Keravel, Y

    2000-11-01

    Thirty two patients with refractory central and neuropathic pain of peripheral origin were treated by chronic stimulation of the motor cortex between May 1993 and January 1997. The mean follow-up was 27. 3 months. The first 24 patients were operated according to the technique described by Tsubokawa. The last 13 cases (8 new patients and 5 reinterventions) were operated by a technique including localization by superficial CT reconstruction of the central region and neuronavigator guidance. The position of the central sulcus was confirmed by the use of intraoperative somatosensory evoked potentials. The somatotopic organisation of the motor cortex was established peroperatively by studying the motor responses at stimulation of the motor cortex through the dura. Ten of the 13 patients with central pain (77%) and nine of the 12 patients with neuropathic facial pain had experienced substantial pain relief (75%). One of the 3 patients with post-paraplegia pain was clearly improved. A satisfactory result was obtained in one patient with pain related to plexus avulsion and in one patient with pain related to intercostal herpes zoster. None of the patients developed epileptic seizures. The position of the stimulating poles effective on pain corresponded to the somatotopic representation of the motor cortex. The neuronavigator localization and guidance technique proved to be most useful identifying the appropriate portion of the motor gyrus. It also allowed the establishment of reliable correlations between electrophysiological-clinical and anatomical data which may be used to improve the clinical results and possibly to extend the indications of this technique. PMID:11084480

  11. Motor training increases the stability of activation patterns in the primary motor cortex.

    Directory of Open Access Journals (Sweden)

    Yi Huang

    Full Text Available Learning to be skillful is an endowed talent of humans, but neural mechanisms underlying behavioral improvement remain largely unknown. Some studies have reported that the mean magnitude of neural activation is increased after learning, whereas others have instead shown decreased activation. In this study, we used functional magnetic resonance imaging (fMRI to investigate learning-induced changes in the neural activation in the human brain with a classic motor training task. Specifically, instead of comparing the mean magnitudes of activation before and after training, we analyzed the learning-induced changes in multi-voxel spatial patterns of neural activation. We observed that the stability of the activation patterns, or the similarity of the activation patterns between the even and odd runs of the fMRI scans, was significantly increased in the primary motor cortex (M1 after training. By contrast, the mean magnitude of neural activation remained unchanged. Therefore, our study suggests that learning shapes the brain by increasing the stability of the activation patterns, therefore providing a new perspective in understanding the neural mechanisms underlying learning.

  12. [Effects of ketamine and urethane on stimulation-induced c-fos expression in neurons of cat visual cortex].

    Science.gov (United States)

    Wang, Ke; Zhu, Hui; Chen, Cui-Yun; Li, Peng; Jin, Cai-Hong; Wang, Zi-Lu; Jiang, San; Hua, Tian-Miao

    2013-12-01

    The effects of ketamine and urethane on neuronal activities remain in debate. As a member of immediate early genes family, the expression of c-fos is stimulation dependent and could be treated as an index to evaluate the strength of neural activities. In this study, SABC immunohistochemical techniques were applied to compare the c-fos expression in neurons of the primary visual cortex (V1) of cats and therefore, to evaluate the effects of acute anesthesia with ketamine HCl and uethane on inhibiting neural activities. Our results showed that compared with control cats, there were no significant differences with the average densities of Nissl-stained V1 neurons in each cortical layers of either urethane or ketamine anesthetized cats. In urethane anesthetized cats, neither the average densities nor the immunoreactive intensities of c-fos positive V1 neurons showed significant difference with that of control ones. However, both the average densities and immunoreactive intensities of c-fos positive V1 neurons in ketamine anesthetized cats decreased significantly compared with that of control and urethane anesthetized cats. These results suggested that ketamine has strong inhibitory effects on the activities of visual cortical neurons, whereas urethane did not. PMID:24415690

  13. A change in injured corticospinal tract originating from the premotor cortex to the primary motor cortex in a patient with intracerebral hemorrhage

    Institute of Scientific and Technical Information of China (English)

    Sang Seok Yeo; Sung Ho Jang

    2012-01-01

    Many studies have attempted to elucidate the motor recovery mechanism of stroke, but the majority of these studies focus on cerebral infarct and relatively little is known about the motor recovery mechanism of intracerebral hemorrhage. In this study, we report on a patient with intracerebral hemorrhage who displayed a change in injured corticospinal tract originating from the premotor cortex to the primary motor cortex on diffusion tensor imaging. An 86-year-old woman presented with complete paralysis of the right extremities following spontaneous intracerebral hemorrhage in the left frontoparietal cortex. The patient showed motor recovery, to the extent of being able to extend affected fingers against gravity and to walk independently on even ground at 5 months after onset. Diffusion tensor imaging showed that the left corticospinal tract originated from the premotor cortex at 1 month after intracerebral hemorrhage and from the left primary motor cortex and premotor cortex at 5 months after intracerebral hemorrhage. The change of injured corticospinal tract originating from the premotor cortex to the primary motor cortex suggests motor recovery of intracerebral hemorrhage.

  14. Oxidative metabolic activity of cerebral cortex after fluid-percussion head injury in the cat.

    Science.gov (United States)

    Duckrow, R B; LaManna, J C; Rosenthal, M; Levasseur, J E; Patterson, J L

    1981-05-01

    To assess the metabolic and vascular effects of head trauma, fluid-percussion pressure waves were transmitted to the brains of anesthetized, paralyzed, and artificially ventilated cats. Changes in the redox state of cytochrome a,a3, and relative local blood volume were measured in situ by dual-wavelength reflection spectrophotometry of the cortical surface viewed through an acrylic cranial window implanted within the closed skull. Initial fluid-percussion impacts of 0.5 to 2.8 atm peak pressure produced consistent transient oxidation of cytochrome a,a3 and increases of cortical blood volume. These changes occurred despite the presence of transient posttraumatic hypotension i some cases. Also, impact-induced alterations of vascular tone occurred, independent of the presence or absence of transient hypertension in the posttraumatic period. These data demonstrate that hypoxia does not play a role in the immediate posttraumatic period in cerebral cortex, and are consistent with the idea that after injury there is increased cortical energy conservation. These data also support the concept that head trauma alters the relationship of metabolism and cerebral circulation in the period immediately after injury. PMID:7229699

  15. Effects of weak amplitude-modulated microwave fields on calcium efflux from awake cat cerebral cortex

    International Nuclear Information System (INIS)

    Calcium (45Ca2+) efflux was studied from preloaded cortex in cats immobilized under local anesthesia, and exposed to a 3.0-mW/cm2 450-MHz field, sinusoidally amplitude modulated at 16 Hz modulation depth 85%). Tissue dosimetry showed a field of 33 V/m in the interhemispheric fissure (rate of energy deposition 0.29 W/kg). Field exposure lasted 60 min. By comparison with controls, efflux curves from field exposed brains were disrupted by waves of increased 45Ca2+ efflux. These waves were irregular in amplitude and duration, but many exhibited periods of 20-30 min. They continued into the postexposure period. Binomial probability analysis indicates that the field-exposed efflux curves constitute a different population from controls at a confidence level of 0.96. In about 70% of cases, initiation of field exposure was followed by increased end-tidal CO2 excretion for about 5 min. However, hypercapnea induced by hypoventilation did not elicit increased 45Ca2+ efflux. Thus this increase with exposure does not appear to arise as a secondary effect of raised cerebral CO2 levels. Radioactivity measurements in cortical samples after superfusion showed 45Ca2+ penetration at about 1.7 mm/hr, consistent with diffusion of the ion in free solution

  16. Motor, cognitive, and affective areas of the cerebral cortex influence the adrenal medulla.

    Science.gov (United States)

    Dum, Richard P; Levinthal, David J; Strick, Peter L

    2016-08-30

    Modern medicine has generally viewed the concept of "psychosomatic" disease with suspicion. This view arose partly because no neural networks were known for the mind, conceptually associated with the cerebral cortex, to influence autonomic and endocrine systems that control internal organs. Here, we used transneuronal transport of rabies virus to identify the areas of the primate cerebral cortex that communicate through multisynaptic connections with a major sympathetic effector, the adrenal medulla. We demonstrate that two broad networks in the cerebral cortex have access to the adrenal medulla. The larger network includes all of the cortical motor areas in the frontal lobe and portions of somatosensory cortex. A major component of this network originates from the supplementary motor area and the cingulate motor areas on the medial wall of the hemisphere. These cortical areas are involved in all aspects of skeletomotor control from response selection to motor preparation and movement execution. The second, smaller network originates in regions of medial prefrontal cortex, including a major contribution from pregenual and subgenual regions of anterior cingulate cortex. These cortical areas are involved in higher-order aspects of cognition and affect. These results indicate that specific multisynaptic circuits exist to link movement, cognition, and affect to the function of the adrenal medulla. This circuitry may mediate the effects of internal states like chronic stress and depression on organ function and, thus, provide a concrete neural substrate for some psychosomatic illness. PMID:27528671

  17. Differential grey matter changes in sensorimotor cortex related to exceptional fine motor skills.

    Directory of Open Access Journals (Sweden)

    M Cornelia Stoeckel

    Full Text Available Functional changes in sensorimotor representation occur in response to use and lesion throughout life. Emerging evidence suggests that functional changes are paralleled by respective macroscopic structural changes. In the present study we used voxel-based morphometry to investigate sensorimotor cortex in subjects with congenitally malformed upper extremities. We expected increased or decreased grey matter to parallel the enlarged or reduced functional representations we reported previously. More specifically, we expected decreased grey matter values in lateral sensorimotor cortex related to compromised hand function and increased grey matter values in medial sensorimotor cortex due to compensatory foot use. We found a medial cluster of grey matter increase in subjects with frequent, hand-like compensatory foot use. This increase was predominantly seen for lateral premotor, supplementary motor, and motor areas and only marginally involved somatosensory cortex. Contrary to our expectation, subjects with a reduced number of fingers, who had shown shrinkage of the functional hand representation previously, did not show decreased grey matter values within lateral sensorimotor cortex. Our data suggest that functional plastic changes in sensorimotor cortex can be associated with increases in grey matter but may also occur in otherwise macroscopically normal appearing grey matter volumes. Furthermore, macroscopic structural changes in motor and premotor areas may be observed without respective changes in somatosensory cortex.

  18. Action Verbs and the Primary Motor Cortex: A Comparative TMS Study of Silent Reading, Frequency Judgments, and Motor Imagery

    Science.gov (United States)

    Tomasino, Barbara; Fink, Gereon R.; Sparing, Roland; Dafotakis, Manuel; Weiss, Peter H.

    2008-01-01

    Single pulse transcranial magnetic stimulation (TMS) was applied to the hand area of the left primary motor cortex or, as a control, to the vertex (STIMULATION: TMS[subscript M1] vs. TMS[subscript vertex]) while right-handed volunteers silently read verbs related to hand actions. We examined three different tasks and time points for stimulation…

  19. Probing the corticospinal link between the motor cortex and motoneurones: some neglected aspects of human motor cortical function

    DEFF Research Database (Denmark)

    Petersen, Nicolas Caesar; Butler, Jane E.; Taylor, Janet L.;

    2010-01-01

    ABSTRACT This review considers the operation of the corticospinal system in primates. There is a relatively widespread cortical area containing corticospinal outputs to a single muscle and thus a motoneurone pool receives corticospinal input from a wide region of cortex. In addition, corticospinal...... magnetic stimulation of the human motor cortex have highlighted the capacity of the cortex to modify its apparent excitability in response to altered afferent inputs, training and various pathologies. Studies using cortical stimulation at 'very low' intensities which elicit only short-latency suppression...... of the discharge of motor units have revealed that the rapidly conducting corticospinal axons (stimulated at higher intensities) contribute to drive motoneurones in normal voluntary contractions. There are also major non-linearities generated at a spinal level in the relation between corticospinal...

  20. The prefrontal cortex shows context-specific changes in effective connectivity to motor or visual cortex during the selection of action or colour

    DEFF Research Database (Denmark)

    Rowe, James B.; Stephan, Klaas E.; Friston, Karl;

    2005-01-01

    used functional magnetic imaging (fMRI) to study the free selection of actions and colours. Control conditions used externally specified actions and colours. The prefrontal cortex was activated during free selection, regardless of modality, in contrast to modality-specific activations outside...... prefrontal cortex. Structural equation modelling (SEM) of fMRI data was used to test the hypothesis that although the same regions of prefrontal cortex may be active in tasks within different domains, there is task-dependent effective connectivity between prefrontal cortex and non-prefrontal cortex. The SEM...... included high-order interactions between modality, selection and regional activity. There was greater coupling between prefrontal cortex and motor cortex during free selection and action tasks, and between prefrontal cortex and visual cortex during free selection of colours. The results suggest that the...

  1. Morphological properties of nociceptive and non-nociceptive neurons in primary somatic cerebral cortex (SI) of cat

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    With the techniques of intracellular recording and labelling, we investigated pain sensation and modulation of the somatic cortical cortex at the neuron's level. After observing the evoked potentials from stimulating the saphenous nerves (SN) of 654 neurons in SI area of the cats, we labelled 30 of the neurons with Neurobiotin to preserve the distribution and the morphologic characteristics of the neurons in the cortex. Based on the tridimensional reconstruction in addition to the eletrophysiological functions, we found clear morphological distinctions between nociceptive and non-nociceptive neurons (P<0.01). This result provided new experimental material to illustrate the function of nociceptive neurons in somatosensory cortex (SI) and presented further evidence to support the "specificity theory" of pain sensation in terms of morphology.

  2. A computational role for bistability and traveling waves in motor cortex

    Directory of Open Access Journals (Sweden)

    Stewart eHeitmann

    2012-09-01

    Full Text Available Adaptive changes in behavior require rapid changes in brain states yet the brain must also remain stable. We investigated two neural mechanisms for evoking rapid transitions between spatiotemporal synchronization patterns of beta oscillations (13--30Hz in motor cortex. Cortex was modeled as a sheet of neural oscillators that were spatially coupled using a center-surround connection topology. Manipulating the inhibitory surround was found to evoke reliable transitions between synchronous oscillation patterns and traveling waves. These transitions modulated the simulated local field potential in agreement with physiological observations in humans. Intermediate levels of surround inhibition were also found to produce bistable coupling topologies that supported both waves and synchrony. State-dependent perturbation between bistable states produced very rapid transitions but were less reliable. We surmise that motor cortex may thus employ state-dependent computation to achieve very rapid changes between bistable motor states when the demand for speed exceeds the demand for accuracy.

  3. Motor imagery in REM sleep is increased by transcranial direct current stimulation of the left motor cortex (C3).

    Science.gov (United States)

    Speth, Jana; Speth, Clemens

    2016-06-01

    This study investigates if anodal transcranial direct current stimulation (tDCS) of areas above the motor cortex (C3) influences the quantity and quality of spontaneous motor imagery experienced in REM sleep. A randomized triple-blinded design was used, combining neurophysiological techniques with a tool of quantitative mentation report analysis developed from cognitive linguistics and generative grammar. The results indicate that more motor imagery, and more athletic motor imagery, is induced by anodal tDCS in comparison to cathodal and sham tDCS. This insight may have implications beyond basic consciousness research. Motor imagery in REM sleep has been hypothesized to serve the rehearsal of motor movements, which benefits later motor performance. Electrophysiological manipulations of motor imagery in REM sleep could in the long run be used for rehabilitative tDCS protocols benefitting temporarily immobile clinical patients, especially those who cannot perform specific motor imagery tasks - such as dementia patients, infants with developmental and motor disorders, and coma patients. PMID:27079954

  4. State- and trait-related alterations of motor cortex excitability in tinnitus patients

    OpenAIRE

    Schecklmann, Martin; Landgrebe, Michael; Kleinjung, Tobias; Frank, Elmar; Rupprecht, Rainer; Sand, Philipp G.; Eichhammer, Peter; Hajak, Göran; Langguth, Berthold

    2014-01-01

    Chronic tinnitus is a brain network disorder with involvement of auditory and non-auditory areas. Repetitive transcranial magnetic stimulation (rTMS) over the temporal cortex has been investigated for the treatment of tinnitus. Several small studies suggest that motor cortex excitability is altered in people with tinnitus. We retrospectively analysed data from 231 patients with chronic tinnitus and 120 healthy controls by pooling data from different studies. Variables of interest were resting...

  5. A computational role for bistability and traveling waves in motor cortex

    OpenAIRE

    Heitmann, Stewart; Gong, Pulin; Breakspear, Michael

    2012-01-01

    Adaptive changes in behavior require rapid changes in brain states yet the brain must also remain stable. We investigated two neural mechanisms for evoking rapid transitions between spatiotemporal synchronization patterns of beta oscillations (13–30 Hz) in motor cortex. Cortex was modeled as a sheet of neural oscillators that were spatially coupled using a center-surround connection topology. Manipulating the inhibitory surround was found to evoke reliable transitions between synchronous osci...

  6. Characterization of the blood-oxygen level-dependent (BOLD) response in cat auditory cortex using high-field fMRI.

    Science.gov (United States)

    Brown, Trecia A; Joanisse, Marc F; Gati, Joseph S; Hughes, Sarah M; Nixon, Pam L; Menon, Ravi S; Lomber, Stephen G

    2013-01-01

    Much of what is known about the cortical organization for audition in humans draws from studies of auditory cortex in the cat. However, these data build largely on electrophysiological recordings that are both highly invasive and provide less evidence concerning macroscopic patterns of brain activation. Optical imaging, using intrinsic signals or dyes, allows visualization of surface-based activity but is also quite invasive. Functional magnetic resonance imaging (fMRI) overcomes these limitations by providing a large-scale perspective of distributed activity across the brain in a non-invasive manner. The present study used fMRI to characterize stimulus-evoked activity in auditory cortex of an anesthetized (ketamine/isoflurane) cat, focusing specifically on the blood-oxygen-level-dependent (BOLD) signal time course. Functional images were acquired for adult cats in a 7 T MRI scanner. To determine the BOLD signal time course, we presented 1s broadband noise bursts between widely spaced scan acquisitions at randomized delays (1-12 s in 1s increments) prior to each scan. Baseline trials in which no stimulus was presented were also acquired. Our results indicate that the BOLD response peaks at about 3.5s in primary auditory cortex (AI) and at about 4.5 s in non-primary areas (AII, PAF) of cat auditory cortex. The observed peak latency is within the range reported for humans and non-human primates (3-4 s). The time course of hemodynamic activity in cat auditory cortex also occurs on a comparatively shorter scale than in cat visual cortex. The results of this study will provide a foundation for future auditory fMRI studies in the cat to incorporate these hemodynamic response properties into appropriate analyses of cat auditory cortex. PMID:23000258

  7. Motor Cortex Plasticity during Unilateral Finger Movement with Mirror Visual Feedback

    Directory of Open Access Journals (Sweden)

    Hatice Kumru

    2016-01-01

    Full Text Available Plasticity is one of the most important physiological mechanisms underlying motor recovery from brain lesions. Rehabilitation methods, such as mirror visual feedback therapy, which are based on multisensory integration of motor, cognitive, and perceptual processes, are considered effective methods to induce cortical reorganization. The present study investigated 3 different types of visual feedback (direct, mirrored, and blocked visual feedback: DVF, MVF, and BVF, resp. on M1 cortex excitability and intracortical inhibition/facilitation at rest and during phasic unimanual motor task in 11 healthy individuals. The excitability of the ipsilateral M1 cortex and the intracortical facilitation increased during motor task performance in the DVF and MVF but not in the BVF condition. In addition, MVF induced cortical disinhibition of the ipsilateral hemisphere to the index finger performing the motor task, which was greater when compared to the BVF and restricted to the homologue first dorsal interosseous muscle. The visual feedback is relevant to M1 cortex excitability modulation but the MVF plays a crucial role in promoting changes in intracortical inhibition in comparison to BVF. Altogether, it can be concluded that a combination of motor training with MVF therapy may induce more robust neuroplastic changes through multisensory integration that is relevant to motor rehabilitation.

  8. Motor Cortex Plasticity during Unilateral Finger Movement with Mirror Visual Feedback.

    Science.gov (United States)

    Kumru, Hatice; Albu, Sergiu; Pelayo, Raul; Rothwell, John; Opisso, Eloy; Leon, Daniel; Soler, Dolor; Tormos, Josep Maria

    2016-01-01

    Plasticity is one of the most important physiological mechanisms underlying motor recovery from brain lesions. Rehabilitation methods, such as mirror visual feedback therapy, which are based on multisensory integration of motor, cognitive, and perceptual processes, are considered effective methods to induce cortical reorganization. The present study investigated 3 different types of visual feedback (direct, mirrored, and blocked visual feedback: DVF, MVF, and BVF, resp.) on M1 cortex excitability and intracortical inhibition/facilitation at rest and during phasic unimanual motor task in 11 healthy individuals. The excitability of the ipsilateral M1 cortex and the intracortical facilitation increased during motor task performance in the DVF and MVF but not in the BVF condition. In addition, MVF induced cortical disinhibition of the ipsilateral hemisphere to the index finger performing the motor task, which was greater when compared to the BVF and restricted to the homologue first dorsal interosseous muscle. The visual feedback is relevant to M1 cortex excitability modulation but the MVF plays a crucial role in promoting changes in intracortical inhibition in comparison to BVF. Altogether, it can be concluded that a combination of motor training with MVF therapy may induce more robust neuroplastic changes through multisensory integration that is relevant to motor rehabilitation. PMID:26881121

  9. Cats

    Science.gov (United States)

    ... those experienced by humans. Cats that hunt wild rodents and rabbits in the western, particularly the southwestern, ... caused by a fungus that can infect skin, hair, and nails of both people and animals. Ringworm ...

  10. Tau Accumulation in Primary Motor Cortex of Variant Alzheimer's Disease with Spastic Paraparesis.

    Science.gov (United States)

    Lyoo, Chul Hyoung; Cho, Hanna; Choi, Jae Yong; Hwang, Mi Song; Hong, Sang Kyoon; Kim, Yun Joong; Ryu, Young Hoon; Lee, Myung Sik

    2016-02-16

    We studied topographic distribution of tau and amyloid-β in a patient with variant Alzheimer's disease with spastic paraparesis (VarAD) by comparing AD patients. The proband developed progressive memory impairment, dysarthria, and spastic paraparesis at age 23. Heterozygous missense mutation (L166P) was found in exon 6 of presenilin-1 gene. The proband showed prominently increased amyloid binding in striatum and cerebellum and asymmetrical tau binding in the primary sensorimotor cortex contralateral to the side more affected by spasticity. We suspect that upper motor neuron dysfunctions may be attributed to excessive abnormal tau accumulation rather than amyloid-β in the primary motor cortex. PMID:26890779

  11. Speech dynamics are coded in the left motor cortex in fluent speakers but not in adults who stutter

    OpenAIRE

    Neef, Nicole E.; Hoang, T. N. Linh; Neef, Andreas; Paulus, Walter; Sommer, Martin

    2015-01-01

    Speech production is a remarkable motor feat, but how the brain orchestrates articulators to produce fluent, well-intonated speech is unclear. Neef et al. verify the proposed uncoupling of motor output cells from motor plan cells in left primary motor cortex in fluent speech, and reveal its disruption in stuttering.

  12. Modulation of motor cortex excitability by physical similarity with an observed hand action.

    Directory of Open Access Journals (Sweden)

    Marie-Christine Désy

    Full Text Available The passive observation of hand actions is associated with increased motor cortex excitability, presumably reflecting activity within the human mirror neuron system (MNS. Recent data show that in-group ethnic membership increases motor cortex excitability during observation of culturally relevant hand gestures, suggesting that physical similarity with an observed body part may modulate MNS responses. Here, we ask whether the MNS is preferentially activated by passive observation of hand actions that are similar or dissimilar to self in terms of sex and skin color. Transcranial magnetic stimulation-induced motor evoked potentials were recorded from the first dorsal interosseus muscle while participants viewed videos depicting index finger movements made by female or male participants with black or white skin color. Forty-eight participants equally distributed in terms of sex and skin color participated in the study. Results show an interaction between self-attributes and physical attributes of the observed hand in the right motor cortex of female participants, where corticospinal excitability is increased during observation of hand actions in a different skin color than that of the observer. Our data show that specific physical properties of an observed action modulate motor cortex excitability and we hypothesize that in-group/out-group membership and self-related processes underlie these effects.

  13. The spinothalamic system targets motor and sensory areas in the cerebral cortex of monkeys.

    Science.gov (United States)

    Dum, Richard P; Levinthal, David J; Strick, Peter L

    2009-11-11

    Classically, the spinothalamic (ST) system has been viewed as the major pathway for transmitting nociceptive and thermoceptive information to the cerebral cortex. There is a long-standing controversy about the cortical targets of this system. We used anterograde transneuronal transport of the H129 strain of herpes simplex virus type 1 in the Cebus monkey to label the cortical areas that receive ST input. We found that the ST system reaches multiple cortical areas located in the contralateral hemisphere. The major targets are granular insular cortex, secondary somatosensory cortex and several cortical areas in the cingulate sulcus. It is noteworthy that comparable cortical regions in humans consistently display activation when subjects are acutely exposed to painful stimuli. We next combined anterograde transneuronal transport of virus with injections of a conventional tracer into the ventral premotor area (PMv). We used the PMv injection to identify the cingulate motor areas on the medial wall of the hemisphere. This combined approach demonstrated that each of the cingulate motor areas receives ST input. Our meta-analysis of imaging studies indicates that the human equivalents of the three cingulate motor areas also correspond to sites of pain-related activation. The cingulate motor areas in the monkey project directly to the primary motor cortex and to the spinal cord. Thus, the substrate exists for the ST system to have an important influence on the cortical control of movement. PMID:19906970

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

    OpenAIRE

    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 ...

  15. Motor Cortex Plasticity during Unilateral Finger Movement with Mirror Visual Feedback

    OpenAIRE

    Hatice Kumru; Sergiu Albu; Raul Pelayo; John Rothwell; Eloy Opisso; Daniel Leon; Dolor Soler; Josep Maria Tormos

    2015-01-01

    Plasticity is one of the most important physiological mechanisms underlying motor recovery from brain lesions. Rehabilitation methods, such as mirror visual feedback therapy, which are based on multisensory integration of motor, cognitive, and perceptual processes, are considered effective methods to induce cortical reorganization. The present study investigated 3 different types of visual feedback (direct, mirrored, and blocked visual feedback: DVF, MVF, and BVF, resp.) on M1 cortex excitabi...

  16. Diversity of layer 5 projection neurons in the mouse motor cortex

    OpenAIRE

    Oswald, Manfred J.; Tantirigama, Malinda L. S.; Sonntag, Ivo; Hughes, Stephanie M.; Ruth M Empson

    2013-01-01

    In the primary motor cortex (M1), layer 5 projection neurons signal directly to distant motor structures to drive movement. Despite their pivotal position and acknowledged diversity these neurons are traditionally separated into broad commissural and corticofugal types, and until now no attempt has been made at resolving the basis for their diversity. We therefore probed the electrophysiological and morphological properties of retrogradely labeled M1 corticospinal (CSp), corticothalamic (CTh)...

  17. Laminarly orthogonal excitation of fast spiking and low threshold spiking interneurons in mouse motor cortex

    OpenAIRE

    Apicella, Alfonso J; Wickersham, Ian R.; Seung, H. Sebastian; Gordon M. G Shepherd

    2012-01-01

    In motor cortex, long-range output to subcortical motor circuits depends on excitatory and inhibitory inputs converging on projection neurons in layers 5A/B. How interneurons interconnect with these projection neurons, and whether these microcircuits are interneuron- and/or projection-specific, is unclear. We found that fast spiking (FS) interneurons received strong intralaminar (horizontal) excitation from pyramidal neurons in layers 5A/B including corticostriatal and corticospinal neurons, ...

  18. Diversity of Layer 5 Projection Neurons in the Mouse Motor Cortex

    OpenAIRE

    Oswald, Manfred J.; Malinda LS Tantirigama; Ivo eSonntag; Hughes, Stephanie M.; Ruth M Empson

    2013-01-01

    In the primary motor cortex (M1), layer 5 projection neurons signal directly to distant motor structures to drive movement. Despite their pivotal position and acknowledged diversity these neurons are traditionally separated into broad commissural and corticofugal types, and until now no attempt has been made at resolving the basis for their diversity. We therefore probed the electrophysiological and morphological properties of retrogradely labelled M1 corticospinal (CSp), corticothalamic (CTh...

  19. Functional lateralization in cingulate cortex predicts motor recovery after basal ganglia stroke.

    Science.gov (United States)

    Li, Yao; Chen, Zengai; Su, Xin; Zhang, Xiaoliu; Wang, Ping; Zhu, Yajing; Xu, Qun; Xu, Jianrong; Tong, Shanbao

    2016-02-01

    The basal ganglia (BG) is involved in higher order motor control such as movement planning and execution of complex motor synergies. Neuroimaging study on stroke patients specifically with BG lesions would help to clarify the consequence of BG damage on motor control. In this paper, we performed a longitudinal study in the stroke patients with lesions in BG regions across three motor recovery stages, i.e., less than 2week (Session 1), 1-3m (Session 2) and more than 3m (Session 3). The patients showed an activation shift from bilateral hemispheres during early sessions (3m), suggesting a compensation effect from the contralesional hemisphere during motor recovery. We found that the lateralization of cerebellum(CB) for affected hand task correlated with patients' concurrent Fugl-Meyer index (FMI) in Session 2. Moreover, the cingulate cortex lateralization index in Session 2 was shown to significantly correlate with subsequent FMI change between Session 3 and Session 2, which serves as a prognostic marker for motor recovery. Our findings consolidated the close interactions between BG and CB during the motor recovery after stroke. The dominance of activation in contralateral cingulate cortex was associated with a better motor recovery, suggesting the important role of ipsilesional attention modulation in the early stage after BG stroke. PMID:26742641

  20. Effects of TMS on different stages of motor and non-motor verb processing in the primary motor cortex.

    Directory of Open Access Journals (Sweden)

    Liuba Papeo

    Full Text Available The embodied cognition hypothesis suggests that motor and premotor areas are automatically and necessarily involved in understanding action language, as word conceptual representations are embodied. This transcranial magnetic stimulation (TMS study explores the role of the left primary motor cortex in action-verb processing. TMS-induced motor-evoked potentials from right-hand muscles were recorded as a measure of M1 activity, while participants were asked either to judge explicitly whether a verb was action-related (semantic task or to decide on the number of syllables in a verb (syllabic task. TMS was applied in three different experiments at 170, 350 and 500 ms post-stimulus during both tasks to identify when the enhancement of M1 activity occurred during word processing. The delays between stimulus onset and magnetic stimulation were consistent with electrophysiological studies, suggesting that word recognition can be differentiated into early (within 200 ms and late (within 400 ms lexical-semantic stages, and post-conceptual stages. Reaction times and accuracy were recorded to measure the extent to which the participants' linguistic performance was affected by the interference of TMS with M1 activity. No enhancement of M1 activity specific for action verbs was found at 170 and 350 ms post-stimulus, when lexical-semantic processes are presumed to occur (Experiments 1-2. When TMS was applied at 500 ms post-stimulus (Experiment 3, processing action verbs, compared with non-action verbs, increased the M1-activity in the semantic task and decreased it in the syllabic task. This effect was specific for hand-action verbs and was not observed for action-verbs related to other body parts. Neither accuracy nor RTs were affected by TMS. These findings suggest that the lexical-semantic processing of action verbs does not automatically activate the M1. This area seems to be rather involved in post-conceptual processing that follows the retrieval of motor

  1. Cerebellar vermis is a target of projections from the motor areas in the cerebral cortex.

    Science.gov (United States)

    Coffman, Keith A; Dum, Richard P; Strick, Peter L

    2011-09-20

    The cerebellum has a medial, cortico-nuclear zone consisting of the cerebellar vermis and the fastigial nucleus. Functionally, this zone is concerned with whole-body posture and locomotion. The vermis classically is thought to be included within the "spinocerebellum" and to receive somatic sensory input from ascending spinal pathways. In contrast, the lateral zone of the cerebellum is included in the "cerebro-cerebellum" because it is densely interconnected with the cerebral cortex. Here we report the surprising result that a portion of the vermis receives dense input from the cerebral cortex. We injected rabies virus into lobules VB-VIIIB of the vermis and used retrograde transneuronal transport of the virus to define disynaptic inputs to it. We found that large numbers of neurons in the primary motor cortex and in several motor areas on the medial wall of the hemisphere project to the vermis. Thus, our results challenge the classical view of the vermis and indicate that it no longer should be considered as entirely isolated from the cerebral cortex. Instead, lobules VB-VIIIB represent a site where the cortical motor areas can influence descending control systems involved in the regulation of whole-body posture and locomotion. We argue that the projection from the cerebral cortex to the vermis is part of the neural substrate for anticipatory postural adjustments and speculate that dysfunction of this system may underlie some forms of dystonia. PMID:21911381

  2. Improvement in precision grip force control with self-modulation of primary motor cortex during motor imagery

    Directory of Open Access Journals (Sweden)

    Maria Laura eBlefari

    2015-02-01

    Full Text Available Motor imagery (MI has shown effectiveness in enhancing motor performance. This may be due to the common neural mechanisms underlying MI and motor execution (ME. The main region of the ME network, the primary motor cortex (M1, has been consistently linked to motor performance. However, the activation of M1 during motor imagery is controversial, which may account for inconsistent rehabilitation therapy outcomes using MI. Here, we examined the relationship between contralateral M1 (cM1 activation during MI and changes in sensorimotor performance. To aid cM1 activity modulation during MI, we used real-time fMRI neurofeedback-guided MI based on cM1 hand area blood oxygen level dependent (BOLD signal in healthy subjects, performing kinesthetic MI of pinching. We used multiple regression analysis to examine the correlation between cM1 BOLD signal and changes in motor performance during an isometric pinching task of those subjects who were able to activate cM1 during motor imagery. Activities in premotor and parietal regions were used as covariates. We found that cM1 activity was positively correlated to improvements in accuracy as well as overall performance improvements, whereas other regions in the sensorimotor network were not. The association between cM1 activation during MI with performance changes indicates that subjects with stronger cM1 activation during MI may benefit more from MI training, with implications towards targeted neurotherapy.

  3. Double representation of the wrist and elbow in human motor cortex

    NARCIS (Netherlands)

    Strother, L.; Medendorp, W.P.; Coros, A.M.; Vilis, T.

    2012-01-01

    Movements of the fingers, hand and arm involve overlapping neural representations in primary motor cortex (M1). Monkey M1 exhibits a coresurround organisation in which cortical representation of the hand and fingers is surrounded by representations of the wrist, elbow and shoulder. A potentially hom

  4. Multitarget Multiscale Simulation for Pharmacological Treatment of Dystonia in Motor Cortex

    Science.gov (United States)

    Neymotin, Samuel A.; Dura-Bernal, Salvador; Lakatos, Peter; Sanger, Terence D.; Lytton, William W.

    2016-01-01

    A large number of physiomic pathologies can produce hyperexcitability in cortex. Depending on severity, cortical hyperexcitability may manifest clinically as a hyperkinetic movement disorder or as epilpesy. We focus here on dystonia, a movement disorder that produces involuntary muscle contractions and involves pathology in multiple brain areas including basal ganglia, thalamus, cerebellum, and sensory and motor cortices. Most research in dystonia has focused on basal ganglia, while much pharmacological treatment is provided directly at muscles to prevent contraction. Motor cortex is another potential target for therapy that exhibits pathological dynamics in dystonia, including heightened activity and altered beta oscillations. We developed a multiscale model of primary motor cortex, ranging from molecular, up to cellular, and network levels, containing 1715 compartmental model neurons with multiple ion channels and intracellular molecular dynamics. We wired the model based on electrophysiological data obtained from mouse motor cortex circuit mapping experiments. We used the model to reproduce patterns of heightened activity seen in dystonia by applying independent random variations in parameters to identify pathological parameter sets. These models demonstrated degeneracy, meaning that there were many ways of obtaining the pathological syndrome. There was no single parameter alteration which would consistently distinguish pathological from physiological dynamics. At higher dimensions in parameter space, we were able to use support vector machines to distinguish the two patterns in different regions of space and thereby trace multitarget routes from dystonic to physiological dynamics. These results suggest the use of in silico models for discovery of multitarget drug cocktails. PMID:27378922

  5. Frontal and motor cortex contributions to response inhibition: evidence from electrocorticography.

    Science.gov (United States)

    Fonken, Yvonne M; Rieger, Jochem W; Tzvi, Elinor; Crone, Nathan E; Chang, Edward; Parvizi, Josef; Knight, Robert T; Krämer, Ulrike M

    2016-04-01

    Changes in the environment require rapid modification or inhibition of ongoing behavior. We used the stop-signal paradigm and intracranial recordings to investigate response preparation, inhibition, and monitoring of task-relevant information. Electrocorticographic data were recorded in eight patients with electrodes covering frontal, temporal, and parietal cortex, and time-frequency analysis was used to examine power differences in the beta (13-30 Hz) and high-gamma bands (60-180 Hz). Over motor cortex, beta power decreased, and high-gamma power increased during motor preparation for both go trials (Go) and unsuccessful stops (US). For successful stops (SS), beta increased, and high-gamma was reduced, indexing the cancellation of the prepared response. In the middle frontal gyrus (MFG), stop signals elicited a transient high-gamma increase. The MFG response occurred before the estimated stop-signal reaction time but did not distinguish between SS and US trials, likely signaling attention to the salient stop stimulus. A postresponse high-gamma increase in MFG was stronger for US compared with SS and absent in Go, supporting a role in behavior monitoring. These results provide evidence for differential contributions of frontal subregions to response inhibition, including motor preparation and inhibitory control in motor cortex and cognitive control and action evaluation in lateral prefrontal cortex. PMID:26864760

  6. Potential mechanisms supporting the value of motor cortex stimulation to treat chronic pain syndromes

    Directory of Open Access Journals (Sweden)

    Marcos Fabio DosSantos

    2016-02-01

    Full Text Available Throughout the first years of the twenty-first century, neurotechnologies such as motor cortex stimulation (MCS, transcranial magnetic stimulation (TMS and transcranial direct current stimulation (tDCS have attracted scientific attention and been considered as potential tools to centrally modulate chronic pain, especially for those conditions more difficult to manage and refractory to all types of available pharmacological therapies. Interestingly, although the role of the motor cortex in pain has not been fully clarified, it is one of the cortical areas most commonly targeted by invasive and non-invasive neuromodulation technologies. Recent studies have provided significant advances concerning the establishment of the clinical effectiveness of primary motor cortex stimulation to treat different chronic pain syndromes. Concurrently, the neuromechanisms related to each method of primary motor cortex (M1 modulation have been unveiled. In this respect, the most consistent scientific evidence originates from MCS studies, which indicate the activation of top-down controls driven by M1 stimulation. This concept has also been applied to explain M1-TMS mechanisms. Nevertheless, activation of remote areas in the brain, including cortical and subcortical structures, has been reported with both invasive and non-invasive methods and the participation of major neurotransmitters (e.g. glutamate, GABA and serotonin as well as the release of endogenous opioids has been demonstrated. In this critical review, the putative mechanisms underlying the use of motor cortex stimulation to provide relief from chronic migraine and other types of chronic pain are discussed. Emphasis is placed on the most recent scientific evidence obtained from chronic pain research studies involving MCS and non-invasive neuromodulation methods (e.g. tDCS and TMS, which are analyzed comparatively.

  7. [Connections between the posterior lateral nucleus of the thalamus and the cortex of the cat suprasylvian gyrus].

    Science.gov (United States)

    Artemenko, D P; Mamonets, T M; Fomovskiĭ, B I

    1975-01-01

    Responses of neurons in the thalamic nucleus lateralis posterior (LP) to the stimulation of area 5b and 21 of the suprasylvian gyrus were studied in unanesthetized immobilized cats. Antidromic responses of these neurons indicate the existence of a direct pathways from LP to area 5b and 21. Such pathways are more extensive to area 5b. Relatively long latencies (1.2--60.0 ms) of antidromic responses show that axons of these neurons are slowly conducting (0.3--16.6 m/s). Short-latent 2--3 ms orthodromic responses to LP neurons indicate the existence of a direct pathway from the suprasylvian cortex to LP. Input to LP from area 5b is more powerful than from area 21. The converence of volleys from both areas is seen in 44% of investigated neurons. The stimulation of the suprasylvian cortex evokes postsynaptic inhibition in the most LP neurons. PMID:1207832

  8. Intracortical inhibition and facilitation in different representations of the human motor cortex.

    Science.gov (United States)

    Chen, R; Tam, A; Bütefisch, C; Corwell, B; Ziemann, U; Rothwell, J C; Cohen, L G

    1998-12-01

    Intracortical inhibition and facilitation in different representations of the human motor cortex. J. Neurophysiol. 80: 2870-2881, 1998. Intracortical inhibition (ICI) and intracortical facilitation (ICF) of the human motor cortex can be studied with paired transcranial magnetic stimulation (TMS). Plastic changes and some neurological disorders in humans are associated with changes in ICI and ICF. Although well characterized in the hand representation, it is not known if ICI and ICF vary across different body part representations. Therefore we studied ICI and ICF in different motor representations of the human motor cortex. The target muscles were rectus abdominus (RA), biceps brachii (BB), abductor pollicis brevis (APB), quadriceps femoris (QF), and abductor hallucis (AH). For each muscle, we measured the rest and active motor thresholds (MTs), the motor-evoked potential (MEP) stimulus-response curve (MEP recruitment), ICI, and ICF. The effects of different interstimulus intervals (ISIs) were studied with a conditioning stimulus (CS) intensity of 80% active MT. The effects of different CS intensities were studied at ISI of 2 ms for ICI and ISI of 15 ms for ICF. MT was lowest for APB, followed by BB, AH, and QF, and was highest for RA. Except for BB, MEP recruitment was generally steeper for muscles with lower MT. ICI and ICF were present in all the motor representations tested. The stimulus intensity necessary to elicit ICI was consistently lower than that required to elicit ICF, suggesting that they are mediated by separate mechanisms. Despite wide differences in MT and MEP recruitment, the absolute CS intensities (expressed as percentage of the stimulator's output) required to elicit ICI and ICF appear unrelated to MT and MEP recruitment in the different muscles tested. These findings suggest that the intracortical mechanisms for inhibition and facilitation in different motor representations are not related to the strength of corticospinal projections. PMID

  9. Inter-individual variability in optimal current direction for transcranial magnetic stimulation of the motor cortex

    DEFF Research Database (Denmark)

    Balslev, Daniela; Braet, Wouter; McAllister, Craig; Miall, R Chris

    We evaluated inter-individual variability in optimal current direction for biphasic transcranial magnetic stimulation (TMS) of the motor cortex. Motor threshold for first dorsal interosseus was detected visually at eight coil orientations in 45 degrees increments. Each participant (n=13) completed...... intensity and side-effects it may be worthwhile to check whether rotating the coil 45 degrees from the traditional posterior-lateral orientation decreases motor threshold....... two experimental sessions. One participant with low test-retest correlation (Pearson's r<0.5) was excluded. In four subjects, visual detection of motor threshold was compared to EMG detection; motor thresholds were very similar and highly correlated (0.94-0.99). Similar with previous studies...

  10. Alterations of motor performance and brain cortex mitochondrial function during ethanol hangover.

    Science.gov (United States)

    Bustamante, Juanita; Karadayian, Analia G; Lores-Arnaiz, Silvia; Cutrera, Rodolfo A

    2012-08-01

    Ethanol has been known to affect various behavioral parameters in experimental animals, even several hours after ethanol (EtOH) is absent from blood circulation, in the period known as hangover. The aim of this study was to assess the effects of acute ethanol hangover on motor performance in association with the brain cortex energetic metabolism. Evaluation of motor performance and brain cortex mitochondrial function during alcohol hangover was performed in mice 6 hours after a high ethanol dose (hangover onset). Animals were injected i.p. either with saline (control group) or with ethanol (3.8 g/kg BW) (hangover group). Ethanol hangover group showed a bad motor performance compared with control animals (p hangover animals showed a 34% decrease in the respiratory control rate as compared with the control group. Mitochondrial complex activities were decreased being the complex I-III the less affected by the hangover condition; complex II-III was markedly decreased by ethanol hangover showing 50% less activity than controls. Complex IV was 42% decreased as compared with control animals. Hydrogen peroxide production was 51% increased in brain cortex mitochondria from the hangover group, as compared with the control animals. Quantification of the mitochondrial transmembrane potential indicated that ethanol injected animals presented 17% less ability to maintain the polarized condition as compared with controls. These results indicate that a clear decrease in proton motive force occurs in brain cortex mitochondria during hangover conditions. We can conclude that a decreased motor performance observed in the hangover group of animals could be associated with brain cortex mitochondrial dysfunction and the resulting impairment of its energetic metabolism. PMID:22608205

  11. Three dimensional morphometric analyses of axon terminals early changes induced by methylmercury intoxication in the adult cat striate cortex.

    Science.gov (United States)

    de Oliveira, Ricardo Bezerra; Gomes Leal, Wallace; Picanço-Diniz, Domingos Luis Wanderley; Torres Neto, João Bento; Lins, Nara; Malm, Olaf; Picanço-Diniz, Cristovam W

    2008-12-01

    The aim of the present report is to investigate in detail morphometric changes of axon terminals of area 17 of adult cat induced by methylmercury intoxication. Six adult male cats (Felix catus), with 12 h day-light cycle and ad libitum water and food regimen, received a single dose of MeHgCl (6.4 mg/kg) dissolved in milk, whereas control subjects (n=6) received only milk. After 30 days, biocytin iontophoretic injections were done into the area 17, (Horsley-Clark coordinates between AP 3.0-6.0) on the crown of the lateral gyrus, near the border with area 18. MeHg and inorganic Hg (Hgi) concentrations were measured in the brain parenchyma of intoxicated cats and corresponded on average to 1.39+/-0.3 and 6.79+/-0.6 ppm (mean+/-s.e.m.) respectively. Twenty four hours after iontophoresis, aldehyde fixed brain sections (200 microm thick), were processed to reveal biocytin labeled terminals. Axonal microscopic 3D reconstructions using Neurolucida software (Microbright Systems Inc.) allowed estimations of boutons, branching points and segment densities for each terminal. Cluster analysis of morphometric axonal features from control and intoxicated group revealed, two distinct axon families (Type I and II) as described elsewhere. Total density values of boutons, branching points and segment densities of intoxicated group, decreased 81, 59 and 91% respectively, as compared to the control group (ANOVA two-way, Bonferroni a priori test pintoxication in the visual cortex. PMID:18835550

  12. Resting‐state connectivity of pre‐motor cortex reflects disability in multiple sclerosis

    DEFF Research Database (Denmark)

    Dogonowski, Anne-Marie; Siebner, Hartwig Roman; Soelberg Sørensen, P.;

    2013-01-01

    Objective To characterize the relationship between motor resting-state connectivity of the dorsal pre-motor cortex (PMd) and clinical disability in patients with multiple sclerosis (MS). Materials and methods A total of 27 patients with relapsing–remitting MS (RR-MS) and 15 patients with secondary...... progressive MS (SP-MS) underwent functional resting-state magnetic resonance imaging. Clinical disability was assessed using the Expanded Disability Status Scale (EDSS). Independent component analysis was used to characterize motor resting-state connectivity. Multiple regression analysis was performed in SPM8...... of left PMd showed a positive linear relation with clinical disability in patients with MS. This effect was stronger when considering the group of patients with RR-MS alone, whereas patients with SP-MS showed no increase in coupling strength between left PMd and the motor resting-state network...

  13. Asymmetric Activation of the Primary Motor Cortex during Observation of a Mirror Reflection of a Hand

    OpenAIRE

    Tominaga, Wataru; Matsubayashi, Jun; Furuya, Makiko; Matsuhashi, Masao; Mima, Tatsuya; Fukuyama, Hidenao; Mitani, Akira

    2011-01-01

    Mirror therapy is an effective technique for pain relief and motor function recovery. It has been demonstrated that magnetic 20-Hz activity is induced in the primary motor cortex (M1) after median nerve stimulation and that the amount of the stimulus-induced 20-Hz activity is decreased when the M1 is activated. In the present study, we investigated how the image or the mirror reflection of a hand holding a pencil modulates the stimulus-induced 20-Hz activity in the M1. Neuromagnetic brain act...

  14. Asymmetrical interhemispheric connections develop in cat visual cortex after early unilateral convergent strabismus: Anatomy, physiology and mechanisms

    Directory of Open Access Journals (Sweden)

    Emmanuel eBui Quoc

    2012-01-01

    Full Text Available In the mammalian primary visual cortex, the corpus callosum contributes to the unification of the visual hemifields that project to the two hemispheres. Its development depends on visual experience. When the latter is abnormal, callosal connections must undergo dramatic anatomical and physiological changes. However, such data are sparse and incomplete. Thus, little is known about the consequences of abnormal postnatal visual experience on the development of callosal connections and their role in unifying representation of the two hemifields. Here, the effects of early unilateral convergent strabismus (a model of abnormal visual experience were fully characterized with respect to the development of the callosal connections in cat visual cortex, an experimental model for humans. Electrophysiological responses and 3D reconstruction of single callosal axons show that abnormally asymmetrical callosal connections develop after unilateral convergent strabismus, resulting from an extension of axonal branches of specific orders in the hemisphere ipsilateral to the deviated eye and a decreased number of nodes and terminals in the other (ipsilateral to the non deviated eye. Furthermore this asymmetrical organization prevents the establishment of a unifying representation of the two visual hemifields. As a general rule, we suggest that crossed and uncrossed retino-geniculo-cortical pathways contribute in succession to the development of the callosal maps in visual cortex.

  15. Corticomuscular coherence between motor cortex, somatosensory areas and forearm muscles in the monkey

    Directory of Open Access Journals (Sweden)

    Claire L Witham

    2010-07-01

    Full Text Available Corticomuscular coherence has previously been reported between primary motor cortex (M1 and contralateral muscles. We examined whether such coherence could also be seen from somatosensory areas. Local field potentials (LFPs were recorded from primary somatosensory cortex (S1; areas 3a and 2 and posterior parietal cortex (PPC area 5 simultaneously with M1 LFP and forearm EMG activity in two monkeys during an index finger flexion task. Significant beta-band (~20 Hz corticomuscular coherence was found in all areas investigated. Directed coherence (Granger causality analysis was used to investigate the direction of effects. Surprisingly, the strongest beta-band directed coherence was in the direction from S1/PPC to muscle; it was much weaker in the ascending direction. Examination of the phase of directed coherence provided estimates of the time delay from cortex to muscle. Delays were longer from M1 (~62 ms for the first dorsal interosseous muscle than from S1/PPC (~36 ms. We then looked at coherence and directed coherence between M1 and S1 for clues to this discrepancy. Directed coherence showed large beta-band effects from S1/PPC to M1, with smaller directed coherence in the reverse direction. The directed coherence phase suggested a delay of ~40 ms from M1 to S1. Corticomuscular coherence from S1/PPC could involve multiple pathways; the most important is probably common input from M1 to S1/PPC and muscles. If correct, this implies that somatosensory cortex receives oscillatory efference copy information from M1 about the motor command. This could allow sensory inflow to be interpreted in the light of its motor context.

  16. Disorders of consciousness: further pathophysiological insights using motor cortex transcranial magnetic stimulation.

    OpenAIRE

    Lapitskaya, Natallia; Coleman, Martin R.; Nielsen, Joergen Feldbaek; Gosseries, Olivia; Maertens de Noordhout, Alain

    2009-01-01

    Transcranial magnetic stimulation (TMS) is a noninvasive means of investigating the function, plasticity, and excitability of the human brain. TMS induces a brief intracranial electrical current, which produces action potentials in excitable cells. Stimulation applied over the motor cortex can be used to measure overall excitability of the corticospinal system, somatotopic representation of muscles, and subsequent plastic changes following injury. The facilitation and inhibition characteristi...

  17. Hypoactivation in right inferior frontal cortex is specifically associated with motor response inhibition in adult ADHD

    OpenAIRE

    Morein-Zamir, Sharon; Dodds, Chris; van Hartevelt, Tim J.; Schwarzkopf, Wolfgang; Sahakian, Barbara; Müller, Ulrich; Robbins, Trevor

    2014-01-01

    Adult ADHD has been linked to impaired motor response inhibition and reduced associated activation in the right inferior frontal cortex (IFC). However, it is unclear whether abnormal inferior frontal activation in adult ADHD is specifically related to a response inhibition deficit or reflects a more general deficit in attentional processing. Using functional magnetic resonance imaging, we tested a group of 19 ADHD patients with no comorbidities and a group of 19 healthy control volunteers on ...

  18. Beta oscillations reflect changes in motor cortex inhibition in healthy ageing.

    OpenAIRE

    Rossiter, H. E.; Davis, E. M.; Clark, E. V.; Boudrias, M. H.; Ward, N.S.

    2014-01-01

    Beta oscillations are involved in movement and have previously been linked to levels of the inhibitory neurotransmitter GABA. We examined changes in beta oscillations during rest and movement in primary motor cortex (M1). Amplitude and frequency of beta power at rest and movement-related beta desynchronization (MRBD) were measured during a simple unimanual grip task and their relationship with age was explored in a group of healthy participants. We were able to show that at rest, increasing a...

  19. FUNCTIONAL RECOVERY FOLLOWING MOTOR CORTEX LESIONS IN NON-HUMAN PRIMATES: EXPERIMENTAL IMPLICATIONS FOR HUMAN STROKE PATIENTS

    OpenAIRE

    Darling, Warren G.; Pizzimenti, Marc A.; Morecraft, Robert J.

    2011-01-01

    This review discusses selected classical works and contemporary research on recovery of contralesional fine hand motor function following lesions to motor areas of the cerebral cortex in non-human primates. Findings from both the classical literature and contemporary studies show that lesions of cortical motor areas induce paresis initially, but are followed by remarkable recovery of fine hand/digit motor function that depends on lesion size and post-lesion training. Indeed, in ...

  20. Transcranial direct current stimulation of the primary motor cortex improves word-retrieval in older adults.

    Directory of Open Access Journals (Sweden)

    Marcus eMeinzer

    2014-09-01

    Full Text Available Language facilitation by transcranial direct current stimulation (tDCS in healthy individuals has generated hope that tDCS may also allow improving language impairment after stroke (aphasia. However, current stimulation protocols have yielded variable results and may require identification of residual language cortex using functional magnetic resonance imaging (fMRI, which complicates incorporation into clinical practice. Based on previous behavioral studies that demonstrated improved language processing by motor system pre-activation, the present study assessed whether tDCS administered to the primary motor cortex (M1 can enhance language functions.This proof-of-concept study employed a sham-tDCS controlled, cross-over, within-subject design and assessed the impact of unilateral excitatory (anodal and bihemispheric (dual tDCS in eighteen healthy older adults during semantic word-retrieval and motor speech tasks. Simultaneous fMRI scrutinized the neural mechanisms underlying tDCS effects.Both active tDCS conditions significantly improved word-retrieval compared to sham-tDCS. The direct comparison of activity elicited by word-retrieval vs. motor-speech trials revealed bilateral frontal activity increases during both anodal- and dual-tDCS compared to sham-tDCS. This effect was driven by more pronounced deactivation of frontal regions during the motor-speech task, while activity during word-retrieval trials was unaffected by the stimulation. No effects were found in M1 and secondary motor regions.Our results show that tDCS administered to M1 can improve word-retrieval in healthy individuals, thereby providing a rationale to explore whether M1-tDCS may offer a novel approach to improve language functions in aphasia. fMRI revealed neural facilitation specifically during motor speech trials, which may have reduced switching costs between the overlapping neural systems for lexical retrieval and speech processing, thereby resulting in improved

  1. The neural response to transcranial magnetic stimulation of the human motor cortex. II. Thalamocortical contributions.

    Science.gov (United States)

    Van Der Werf, Ysbrand D; Sadikot, Abbas F; Strafella, Antonio P; Paus, Tomás

    2006-11-01

    Beta oscillations (15-30 Hz) constitute an important electrophysiological signal recorded in the resting state over the human precentral gyrus. The brain circuitry involved in generating the beta oscillations is not well understood but appears to involve both cortical and subcortical structures. We have shown that single pulses of transcranial magnetic stimulation (TMS) applied over the primary motor cortex consistently elicit a brief beta oscillation. Reducing the local cortical excitability using low-frequency repetitive TMS does not change the amplitude of the induced beta oscillation (Van Der Werf and Paus in Exp Brain Res DOI 10.1007/s00221-006-0551-2). Here, we investigated the possible involvement of the thalamus in the cortically expressed beta response to single-pulse TMS. We included eight patients with Parkinson's disease who had undergone unilateral surgical lesioning of the ventrolateral nucleus of the thalamus. We administered 50 single pulses of TMS, at an intensity of 120% of resting motor threshold, over the left and right primary motor cortex and, at the same time, recorded the electroencephalogram (EEG) using a 60-electrode cap. We were able to perform analyses on seven EEG data sets and found that stimulation of the unoperated hemisphere (with thalamus) resulted in higher amplitudes of the single-trial induced beta oscillations than in the operated hemisphere (with thalamotomy). The beta oscillation obtained in response to pulses applied over the unoperated hemisphere was also higher than that obtained in healthy controls. We suggest that (1) the beta oscillatory response to pulses of TMS applied over the primary motor cortex is higher in Parkinson's disease patients, (2) thalamotomy serves to reduce the abnormally high TMS-induced beta oscillations, and (3) the motor thalamus facilitates the cortically generated oscillation, through cortico-subcortico-cortical feedback loops. PMID:16832683

  2. Local-Circuit Phenotypes of Layer 5 Neurons in Motor-Frontal Cortex of YFP-H Mice

    OpenAIRE

    Sheets, Patrick L; Shepherd, Gordon M. G.

    2008-01-01

    Layer 5 pyramidal neurons comprise an important but heterogeneous group of cortical projection neurons. In motor-frontal cortex, these neurons are centrally involved in the cortical control of movement. Recent studies indicate that local excitatory networks in mouse motor-frontal cortex are dominated by descending pathways from layer 2/3 to 5. However, those pathways were identified in experiments involving unlabeled neurons in wild type mice. Here, to explore the possibility of class-specifi...

  3. Pathways and genes differentially expressed in the motor cortex of patients with sporadic amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Santama Niovi

    2007-01-01

    Full Text Available Abstract Background Amyotrophic lateral sclerosis (ALS is a fatal disorder caused by the progressive degeneration of motoneurons in brain and spinal cord. Despite identification of disease-linked mutations, the diversity of processes involved and the ambiguity of their relative importance in ALS pathogenesis still represent a major impediment to disease models as a basis for effective therapies. Moreover, the human motor cortex, although critical to ALS pathology and physiologically altered in most forms of the disease, has not been screened systematically for therapeutic targets. Results By whole-genome expression profiling and stringent significance tests we identify genes and gene groups de-regulated in the motor cortex of patients with sporadic ALS, and interpret the role of individual candidate genes in a framework of differentially expressed pathways. Our findings emphasize the importance of defense responses and cytoskeletal, mitochondrial and proteasomal dysfunction, reflect reduced neuronal maintenance and vesicle trafficking, and implicate impaired ion homeostasis and glycolysis in ALS pathogenesis. Additionally, we compared our dataset with publicly available data for the SALS spinal cord, and show a high correlation of changes linked to the diseased state in the SALS motor cortex. In an analogous comparison with data for the Alzheimer's disease hippocampus we demonstrate a low correlation of global changes and a moderate correlation for changes specifically linked to the SALS diseased state. Conclusion Gene and sample numbers investigated allow pathway- and gene-based analyses by established error-correction methods, drawing a molecular portrait of the ALS motor cortex that faithfully represents many known disease features and uncovers several novel aspects of ALS pathology. Contrary to expectations for a tissue under oxidative stress, nuclear-encoded mitochondrial genes are uniformly down-regulated. Moreover, the down-regulation of

  4. Intrahemispheric dysfunction in primary motor cortex without corpus callosum: a transcranial magnetic stimulation study

    Directory of Open Access Journals (Sweden)

    Lassonde Maryse

    2006-06-01

    Full Text Available Abstract Background The two human cerebral hemispheres are continuously interacting, through excitatory and inhibitory influences and one critical structure subserving this interhemispheric balance is the corpus callosum. Interhemispheric neurophysiological abnormalities and intrahemispheric behavioral impairments have been reported in individuals lacking the corpus callosum. The aim of this study was to examine intrahemispheric neurophysiological function in primary motor cortex devoid of callosal projections. Methods Intracortical excitatory and inhibitory systems were tested in three individuals with complete agenesis of the corpus callosum and sixteen healthy individuals. These systems were assessed using transcranial magnetic stimulation (TMS protocols: motor threshold at rest, paired-pulse curve, and cortical silent period. Results TMS revealed no difference between the patient and control groups on the motor threshold measure, as well as intracortical facilitation and intracortical inhibition systems as tested by paired stimulation. However, intrahemispheric inhibitory function was found to be abnormal in participants without callosal projections, as the cortical silent period duration was significantly increased in the patient group. Conclusion These data suggest that in addition to previously reported impaired interhemispheric function, patients lacking the entire corpus callosum also display abnormal intrahemispheric excitability of the primary motor cortex.

  5. Sensory-evoked and spontaneous gamma and spindle bursts in neonatal rat motor cortex.

    Science.gov (United States)

    An, Shuming; Kilb, Werner; Luhmann, Heiko J

    2014-08-13

    Self-generated neuronal activity originating from subcortical regions drives early spontaneous motor activity, which is a hallmark of the developing sensorimotor system. However, the neural activity patterns and role of primary motor cortex (M1) in these early movements are still unknown. Combining voltage-sensitive dye imaging (VSDI) with simultaneous extracellular multielectrode recordings in postnatal day 3 (P3)-P5 rat primary somatosensory cortex (S1) and M1 in vivo, we observed that tactile forepaw stimulation induced spindle bursts in S1 and gamma and spindle bursts in M1. Approximately 40% of the spontaneous gamma and spindle bursts in M1 were driven by early motor activity, whereas 23.7% of the M1 bursts triggered forepaw movements. Approximately 35% of the M1 bursts were uncorrelated to movements and these bursts had significantly fewer spikes and shorter burst duration. Focal electrical stimulation of layer V neurons in M1 mimicking physiologically relevant 40 Hz gamma or 10 Hz spindle burst activity reliably elicited forepaw movements. We conclude that M1 is already involved in somatosensory information processing during early development. M1 is mainly activated by tactile stimuli triggered by preceding spontaneous movements, which reach M1 via S1. Only a fraction of M1 activity transients trigger motor responses directly. We suggest that both spontaneously occurring and sensory-evoked gamma and spindle bursts in M1 contribute to the maturation of corticospinal and sensorimotor networks required for the refinement of sensorimotor coordination. PMID:25122889

  6. Interplay of orientation selectivity and the power of low- and high-gamma bands in the cat primary visual cortex.

    Science.gov (United States)

    Bharmauria, Vishal; Bachatene, Lyes; Ouelhazi, Afef; Cattan, Sarah; Chanauria, Nayan; Etindele-Sosso, Faustin Armel; Rouat, Jean; Molotchnikoff, Stéphane

    2016-05-01

    Gamma oscillations are ubiquitous in brain and are believed to be inevitable for information processing in brain. Here, we report that distinct bands (low, 30-40Hz and high gamma, 60-80Hz) of stimulus-triggered gamma oscillations are systematically linked to the orientation selectivity index (OSI) of neurons in the cat primary visual cortex. The gamma-power is high for the highly selective neurons in the low-gamma band, whereas it is high for the broadly selective neurons in the high-gamma band. We suggest that the low-gamma band is principally implicated in feed-forward excitatory flow, whereas the high-gamma band governs the flow of this excitation. PMID:27033667

  7. Inflammation and neuronal death in the motor cortex of the wobbler mouse, an ALS animal model

    DEFF Research Database (Denmark)

    Dahlke, Carolin; Saberi, Darius; Ott, Bastian;

    2015-01-01

    microscopy, and transmission electron microscopy techniques, we analyze the proliferation behavior of microglial cells and astrocytes. We also investigate possible motor neuron death in the mouse motor cortex at different stages of the wobbler disease, which so far has not received much attention. Results An...... area show caspase 3 activation indicating neurodegenerative processes, which may cause progressive paralysis of the WR mice. It could also cause cell degeneration, such as vacuolization, dilation of the ER, and swollen mitochondria at the same time, and support the assumption that inflammation might be...... the immune response is primary or secondary and how harmful or beneficial it is in the WR motor neuron disease, anti-inflammatory treatment might be considered....

  8. Melodic Priming of Motor Sequence Performance: The Role of the Dorsal Premotor Cortex

    Science.gov (United States)

    Stephan, Marianne A.; Brown, Rachel; Lega, Carlotta; Penhune, Virginia

    2016-01-01

    The purpose of this study was to determine whether exposure to specific auditory sequences leads to the induction of new motor memories and to investigate the role of the dorsal premotor cortex (dPMC) in this crossmodal learning process. Fifty-two young healthy non-musicians were familiarized with the sound to key-press mapping on a computer keyboard and tested on their baseline motor performance. Each participant received subsequently either continuous theta burst stimulation (cTBS) or sham stimulation over the dPMC and was then asked to remember a 12-note melody without moving. For half of the participants, the contour of the melody memorized was congruent to a subsequently performed, but never practiced, finger movement sequence (Congruent group). For the other half, the melody memorized was incongruent to the subsequent finger movement sequence (Incongruent group). Hearing a congruent melody led to significantly faster performance of a motor sequence immediately thereafter compared to hearing an incongruent melody. In addition, cTBS speeded up motor performance in both groups, possibly by relieving motor consolidation from interference by the declarative melody memorization task. Our findings substantiate recent evidence that exposure to a movement-related tone sequence can induce specific, crossmodal encoding of a movement sequence representation. They further suggest that cTBS over the dPMC may enhance early offline procedural motor skill consolidation in cognitive states where motor consolidation would normally be disturbed by concurrent declarative memory processes. These findings may contribute to a better understanding of auditory-motor system interactions and have implications for the development of new motor rehabilitation approaches using sound and non-invasive brain stimulation as neuromodulatory tools. PMID:27242414

  9. The Effect of Aerobic Exercise on Neuroplasticity within the Motor Cortex following Stroke

    Science.gov (United States)

    Murdoch, Kate; Buckley, Jonathan D.; McDonnell, Michelle N.

    2016-01-01

    Background Aerobic exercise is associated with enhanced plasticity in the motor cortex of healthy individuals, but the effect of aerobic exercise on neuroplasticity following a stroke is unknown. Objective The aim of this study was to compare corticomotoneuronal excitability and neuroplasticity in the upper limb cortical representation following a single session of low intensity lower limb cycling, or a rest control condition. Methods We recruited chronic stroke survivors to take part in three experimental conditions in a randomised, cross-over design. Corticomotoneuronal excitability was examined using transcranial magnetic stimulation to elicit motor evoked potentials in the affected first dorsal interosseus muscle. Following baseline measures, participants either cycled on a stationary bike at a low exercise intensity for 30 minutes, or remained resting in a seated position for 30 minutes. Neuroplasticity within the motor cortex was then examined using an intermittent theta burst stimulation (iTBS) paradigm. During the third experimental condition, participants cycled for the 30 minutes but did not receive any iTBS. Results Twelve participants completed the study. We found no significant effect of aerobic exercise on corticomotoneuronal excitability when compared to the no exercise condition (P > 0.05 for all group and time comparisons). The use of iTBS did not induce a neuroplastic-like response in the motor cortex with or without the addition of aerobic exercise. Conclusions Our results suggest that following a stroke, the brain may be less responsive to non-invasive brain stimulation paradigms that aim to induce short-term reorganisation, and aerobic exercise was unable to induce or improve this response. PMID:27018862

  10. Computational modelling of movement-related beta-oscillatory dynamics in human motor cortex.

    Science.gov (United States)

    Bhatt, Mrudul B; Bowen, Stephanie; Rossiter, Holly E; Dupont-Hadwen, Joshua; Moran, Rosalyn J; Friston, Karl J; Ward, Nick S

    2016-06-01

    Oscillatory activity in the beta range, in human primary motor cortex (M1), shows interesting dynamics that are tied to behaviour and change systematically in disease. To investigate the pathophysiology underlying these changes, we must first understand how changes in beta activity are caused in healthy subjects. We therefore adapted a canonical (repeatable) microcircuit model used in dynamic causal modelling (DCM) previously used to model induced responses in visual cortex. We adapted this model to accommodate cytoarchitectural differences between visual and motor cortex. Using biologically plausible connections, we used Bayesian model selection to identify the best model of measured MEG data from 11 young healthy participants, performing a simple handgrip task. We found that the canonical M1 model had substantially more model evidence than the generic canonical microcircuit model when explaining measured MEG data. The canonical M1 model reproduced measured dynamics in humans at rest, in a manner consistent with equivalent studies performed in mice. Furthermore, the changes in excitability (self-inhibition) necessary to explain beta suppression during handgrip were consistent with the attenuation of sensory precision implied by predictive coding. These results establish the face validity of a model that can be used to explore the laminar interactions that underlie beta-oscillatory dynamics in humans in vivo. Our canonical M1 model may be useful for characterising the synaptic mechanisms that mediate pathophysiological beta dynamics associated with movement disorders, such as stroke or Parkinson's disease. PMID:26956910

  11. Low Doses of Ethanol Enhance LTD-like Plasticity in Human Motor Cortex.

    Science.gov (United States)

    Fuhl, Anna; Müller-Dahlhaus, Florian; Lücke, Caroline; Toennes, Stefan W; Ziemann, Ulf

    2015-12-01

    Humans liberally use ethanol for its facilitating effects on social interactions but its effects on central nervous system function remain underexplored. We have recently described that very low doses of ethanol abolish long-term potentiation (LTP)-like plasticity in human cortex, most likely through enhancement of tonic inhibition [Lücke et al, 2014, Neuropsychopharmacology 39:1508-18]. Here, we studied the effects of low-dose ethanol on long-term depression (LTD)-like plasticity. LTD-like plasticity was induced in human motor cortex by paired associative transcranial magnetic stimulation (PASLTD), and measured as decreases of motor evoked potential input-output curve (IO-curve). In addition, sedation was measured by decreases in saccade peak velocity (SPV). Ethanol in two low doses (EtOHSPV. Non-sedating low doses of ethanol, easily reached during social drinking, enhance LTD-like plasticity in human cortex. This effect is most likely explained by the activation of extrasynaptic α4-subunit containing gamma-aminobutyric type A receptors by low-dose EtOH, resulting in increased tonic inhibition. Findings may stimulate cellular research on the role of tonic inhibition in regulating excitability and plasticity of cortical neuronal networks. PMID:26038159

  12. The effects of acute alcohol exposure on the response properties of neurons in visual cortex area 17 of cats

    International Nuclear Information System (INIS)

    Physiological and behavioral studies have demonstrated that a number of visual functions such as visual acuity, contrast sensitivity, and motion perception can be impaired by acute alcohol exposure. The orientation- and direction-selective responses of cells in primary visual cortex are thought to participate in the perception of form and motion. To investigate how orientation selectivity and direction selectivity of neurons are influenced by acute alcohol exposure in vivo, we used the extracellular single-unit recording technique to examine the response properties of neurons in primary visual cortex (A17) of adult cats. We found that alcohol reduces spontaneous activity, visual evoked unit responses, the signal-to-noise ratio, and orientation selectivity of A17 cells. In addition, small but detectable changes in both the preferred orientation/direction and the bandwidth of the orientation tuning curve of strongly orientation-biased A17 cells were observed after acute alcohol administration. Our findings may provide physiological evidence for some alcohol-related deficits in visual function observed in behavioral studies.

  13. The role of plastic changes in the motor cortex and spinal cord for motor learning

    DEFF Research Database (Denmark)

    Nielsen, Jens Bo; Lundbye-Jensen, Jesper

    key players in the early stages of skill acquisition and consolidation of motor learning. Expansion of the cortical representation of the trained muscles, changes in corticomuscular coupling and changes in stretch reflex activity are thus all markers of neuroplastic changes accompanying early skill...... acquisition. We have shown in recent experiments that sensory feedback from the active muscles play a surprisingly specific role at this stage of learning. Following motor skill training, repeated activation of sensory afferents from the muscle that has been involved in a previous training session, interfered...

  14. Age-related changes in soma size of neurons in the spinal cord motor column of the cat.

    Science.gov (United States)

    Liu, R H; Bertolotto, C; Engelhardt, J K; Chase, M H

    1996-06-28

    The present study was undertaken to examine the effect of the aging process on the soma size and number of motoneurons and interneurons in the motor column of the spinal cord of old cats. Neurons in the motor column were divided into small and large populations based on a bimodal distribution of their soma cross-sectional areas. A 17% decrease in the cross-sectional area of small neurons was observed, this decrease was statistically significant (P cats compared with the control animals. This data suggest that neurons in the motor column are not uniformly affected by the aging process because morphological changes are proportionally greater in small neurons than in large neurons. PMID:8817566

  15. Dopaminergic mesocortical projections to M1: role in motor learning and motor cortex plasticity

    Directory of Open Access Journals (Sweden)

    Jonas Aurel Hosp

    2013-10-01

    Full Text Available Although the architecture of a dopaminergic (DA system within the primary motorcortex (M1 was well characterized anatomically, its functional significance remainedobscure for a long time. Recent studies in rats revealed that the integrity ofdopaminergic fibers in M1 is a prerequisite for successful acquisition of motor skills.This essential contribution of DA for motor learning is plausible as it modulates M1circuitry at multiple levels thereby promoting plastic changes that are required forinformation storage: at the network level, DA increases cortical excitability andenhances the stability of motor maps. At the cellular level, DA induces the expressionof learning related genes via the transcription factor c-fos. At the level of synapses,DA is required for the formation of long-term potentiation (LTP, a mechanism thatlikely is a fingerprint of a motor memory trace within M1. Dopaminergic fibersinnervating M1 originate within the midbrain, precisely the ventral tegmental area(VTA and the medial portion of substantia nigra (SN. Thus, they could be part of themeso-cortico-limibic pathway – a network that provides information about saliencyand motivational value of an external stimulus and is commonly referred as

  16. Recurrent CSPs after Transcranial Magnetic Stimulation of Motor Cortex in Restless Legs Syndrome

    Directory of Open Access Journals (Sweden)

    Aulikki Ahlgrén-Rimpiläinen

    2012-01-01

    Full Text Available Aims. The aim of this study was to investigate the motor control and central silent period (CSP in restless legs syndrome (RLS. Methods. Transcranial magnetic stimulation was focused on the dominant and nondominant hemispheric areas of motor cortex in six subjects with RLS and six controls. The responses were recorded on the contralateral abductor digiti minimi (ADM and tibialis anterior (TA muscles with intramuscular needle electrodes. Results. No significant differences were found in the motor conduction or central motor conduction time, in the latency, or in the duration of the CSPs between or within the groups, but multiple CSPs were observed in both groups. The number of the CSPs was significantly higher in both ADMs and in the dominant TA (P≤0.01 in the RLS group compared to the controls. Conclusion. Descending motor pathways functioned correctly in both groups. The occurrence of the recurrent CSPs predominantly in the RLS group could be a sign of a change of function in the inhibitory control system. Further research is needed to clarify the role of the intramuscular recording technique and especially the role of the subcortical generators in the feedback regulation of the central nervous system in RLS.

  17. The Emergence of Contrast-Invariant Orientation Tuning in Simple Cells of Cat Visual Cortex

    OpenAIRE

    Finn, Ian M.; Priebe, Nicholas J.; Ferster, David

    2007-01-01

    Simple cells in primary visual cortex exhibit contrast-invariant orientation tuning, in seeming contradiction to feed-forward models relying on lateral geniculate nucleus (LGN) input alone. Contrast invariance has therefore been thought to depend on the presence of intracortical lateral inhibition. In vivo intracellular recordings instead suggest that contrast invariance can be explained by three properties of the excitatory pathway. 1) Depolarizations evoked by orthogonal stimuli are determi...

  18. ON AND OFF DOMAINS OF GENICULATE AFFERENTS IN CAT PRIMARY VISUAL CORTEX

    OpenAIRE

    Jin, J. Z.; Weng, C.; Yeh, C. I.; Gordon, J A; RUTHAZER, E.S.; Stryker, M.P.; Swadlow, H A; Alonso, J M

    2007-01-01

    On- and off-center geniculate afferents form two major channels of visual processing that are thought to converge in the primary visual cortex. However, humans with severely reduced on-responses can have normal visual acuity when tested in a white background, which indicates that off-channels can function relatively independently of on-channels under certain conditions. Consistent with this functional independence of channels, here we demonstrate that on- and off-center geniculate afferents s...

  19. A Postnatal Critical Period for Orientation Plasticity in the Cat Visual Cortex

    OpenAIRE

    Shigeru Tanaka; Toshiki Tani; Jérôme Ribot; Kazunori O'Hashi; Kazuyuki Imamura

    2009-01-01

    Orientation selectivity of primary visual cortical neurons is an important requisite for shape perception. Although numerous studies have been previously devoted to a question of how orientation selectivity is established and elaborated in early life, how the susceptibility of orientation plasticity to visual experience changes in time remains unclear. In the present study, we showed a postnatal sensitive period profile for the modifiability of orientation selectivity in the visual cortex of ...

  20. Histone H3 acetylation in the postmortem Parkinson's disease primary motor cortex.

    Science.gov (United States)

    Gebremedhin, Kibrom G; Rademacher, David J

    2016-08-01

    Although the role of epigenetics in Parkinson's disease (PD) has not been extensively studied, α-synuclein, the main component of Lewy bodies, decreased histone H3 acetylation. Here, we determined if there were histone acetylation changes in the primary motor cortex which, according to the Braak model, is one of the last brain regions affected in PD. Net histone H3 acetylation, histone H3 lysine 9 (H3K9), histone H3 lysine 14 (H3K14), histone H3 lysine 18 (H3K18), and histone H3 lysine 23 (H3K23) acetylation was assessed in the primary motor cortex of those affected and unaffected by PD. There was net increase in histone H3 acetylation due to increased H3K14 and H3K18 acetylation. There was a decrease in H3K9 acetylation. No between-groups difference was detected in H3K23 acetylation. Relationships between Unified Lewy Body Staging scores and histone H3 acetylation and substantia nigra depigmentation scores and histone H3 acetylation were observed. No relationships were detected between postmortem interval and histone H3 acetylation and expired age and histone H3 acetylation. These correlational data support the notion that the histone H3 acetylation changes observed here are not due to the postmortem interval or aging. Instead, they are due to PD and/or factors that covary with PD. The data suggest enhanced gene transcription in the primary motor cortex of the PD brain due to increase H3K14 and H3K18 acetylation. This effect is partially offset by a decreased H3K9 acetylation, which might repress gene transcription. PMID:27241718

  1. Enhancing motor network activity using real-time functional MRI neurofeedback of left premotor cortex

    Directory of Open Access Journals (Sweden)

    Theo Ferreira Marins

    2015-12-01

    Full Text Available 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 motor imagery, 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.

  2. The responses to illusory contours of neurons in cortex areas 17 and 18 of the cats

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Responses to illusory contours (ICs) were sampled from neurons incortical areas 17 and 18 of the anesthetized cats. For ICs sensitive cells, the differences of receptive field properties were compared when ICs and real contour stimuli were applied. Two hundred orientation or direction selective cells were studied. We find that about 42 percent of these cells were the ICs sensitive cells. Although their orientation or direction tuning curves to ICs bar and real bars were similar, the response modes (especially latency and time course) were different. The cells' responses to ICs were independent of the spatial phases of sinusoidal gratings, which composed the ICs. The cells' optimal spatial frequency to composing gratings the ICs was much higher than the one to moving gratings. Therefore, these cells really responded to the ICs rather than the line ends of composing gratings. For some kinds of velocity-tuning cells, the optimal velocity to moving ICs bar was much lower than the optimal velocity to moving bars. The present results demonstrate that some cells in areas 17 and 18 of cats have the ability to respond to ICs and have different response properties of the receptive fields to ICs and luminance boundaries via different neural mechanisms.

  3. Vitamin D and Caudal Primary Motor Cortex: A Magnetic Resonance Spectroscopy Study

    OpenAIRE

    Annweiler, Cedric; Beauchet, Olivier; Bartha, Robert; Hachinski, Vladimir; Montero-Odasso, Manuel; ,

    2014-01-01

    Background Vitamin D is involved in brain physiology and lower-extremity function. We investigated spectroscopy in a cohort of older adults to explore the hypothesis that lower vitamin D status was associated with impaired neuronal function in caudal primary motor cortex (cPMC) measured by proton magnetic resonance spectroscopic imaging. Methods Twenty Caucasian community-dwellers (mean±standard deviation, 74.6±6.2 years; 35.0% female) from the ‘Gait and Brain Study’ were included in this ana...

  4. A novel dual-site transcranial magnetic stimulation paradigm to probe fast facilitatory inputs from ipsilateral dorsal premotor cortex to primary motor cortex

    DEFF Research Database (Denmark)

    Groppa, Sergiu; Werner-Petroll, Nicole; Münchau, Alexander;

    2012-01-01

    The dorsal premotor cortex (PMd) plays an import role in action control, sensorimotor integration and motor recovery. Animal studies and human data have demonstrated direct connections between ipsilateral PMd and primary motor cortex hand area (M1(HAND)). In this study we adopted a multimodal...... approach combining highly focal dual-site TMS (dsTMS) and diffusion tensor imaging (DTI) to probe ipsilateral effective and structural connectivity between PMd and M1(HAND) in humans. A suprathreshold test stimulus (TS) was applied to left M1(HAND) producing a motor evoked potential (MEP) and a subsequent...... voluntary contraction of the target muscle. During a two-choice reaction time task, PMd-M1(HAND) facilitation was only observed when dsTMS was given 125 ms after presentation of the cue and subjects responded with their right hand, but not for left hand responses. Our results reveal a short-latency PMd to M...

  5. Motor preparatory activity in posterior parietal cortex is modulated by subjective absolute value.

    Directory of Open Access Journals (Sweden)

    Asha Iyer

    Full Text Available For optimal response selection, the consequences associated with behavioral success or failure must be appraised. To determine how monetary consequences influence the neural representations of motor preparation, human brain activity was scanned with fMRI while subjects performed a complex spatial visuomotor task. At the beginning of each trial, reward context cues indicated the potential gain and loss imposed for correct or incorrect trial completion. FMRI-activity in canonical reward structures reflected the expected value related to the context. In contrast, motor preparatory activity in posterior parietal and premotor cortex peaked in high "absolute value" (high gain or loss conditions: being highest for large gains in subjects who believed they performed well while being highest for large losses in those who believed they performed poorly. These results suggest that the neural activity preceding goal-directed actions incorporates the absolute value of that action, predicated upon subjective, rather than objective, estimates of one's performance.

  6. On the functional organization and operational principles of the motor cortex

    DEFF Research Database (Denmark)

    Capaday, Charles; Ethier, Christian; Van Vreeswijk, Carl;

    2013-01-01

    Recent studies on the functional organization and operational principles of the motor cortex (MCx), taken together, strongly support the notion that the MCx controls the muscle synergies subserving movements in an integrated manner. For example, during pointing the shoulder, elbow and wrist muscles...... appear to be controlled as a coupled functional system, rather than singly and separately. The recurrent pattern of intrinsic synaptic connections between motor cortical points is likely part of the explanation for this operational principle. So too is the reduplicated, non-contiguous and intermingled...... circuitry. It will be suggested that both operational principles are probably involved. We also discuss the neural mechanisms by which cortical points may be dynamically linked to synthesize movement related muscle synergies. Separate corticospinal outputs sum linearly and lead to a blending of the...

  7. Comparison of functional recovery of manual dexterity after unilateral spinal cord lesion or motor cortex lesion in adult macaque monkeys

    Directory of Open Access Journals (Sweden)

    Florence eHoogewoud

    2013-07-01

    Full Text Available In relation to mechanisms involved in functional recovery of manual dexterity from cervical cord injury or from motor cortical injury, our goal was to determine whether the movements that characterize post-lesion functional recovery are comparable to original movement patterns or do monkeys adopt distinct strategies to compensate the deficits depending on the type of lesion? To this aim, data derived from earlier studies, using a skilled finger task (the modified Brinkman board from which pellets are retrieved from vertical or horizontal slots, in spinal cord and motor cortex injured monkeys were analyzed and compared. Twelve adult macaque monkeys were subjected to a hemi-section of the cervical cord (n=6 or to a unilateral excitotoxic lesion of the hand representation in the primary motor cortex (n=6. In addition, in each subgroup, one half of monkeys (n=3 were treated for 30 days with a function blocking antibody against the neurite growth inhibitory protein Nogo-A, while the other half (n=3 represented control animals. The motor deficits, and the extent and time course of functional recovery were assessed.For some of the parameters investigated (wrist angle for horizontal slots and movement types distribution for vertical slots after cervical injury; movement types distribution for horizontal slots after motor cortex lesion, post-lesion restoration of the original movement patterns (true recovery led to a quantitatively better functional recovery. In the motor cortex lesion groups, pharmacological reversible inactivation experiments showed that the peri-lesion territory of the primary motor cortex or re-arranged, spared domain of the lesion zone, played a major role in the functional recovery, together with the ipsilesional intact premotor cortex.

  8. Influence of repetitive peripheral magnetic stimulation on neural plasticity in the motor cortex related to swallowing.

    Science.gov (United States)

    Momosaki, Ryo; Kakuda, Wataru; Yamada, Naoki; Abo, Masahiro

    2016-09-01

    The aim of this study was to evaluate the effect of repetitive peripheral magnetic stimulation at two different frequencies (20 and 30 Hz) on cortical excitability in motor areas related to swallowing in healthy individuals. The study participants were 10 healthy normal volunteers (two women and eight men, age range 25-36 years). Repetitive peripheral magnetic stimulation was applied to the submandibular muscle using a parabolic coil at the site where contraction of the suprahyoid muscles was elicited. Stimulation was continued for 10 min (total 1200 pulses) at 20 Hz on 1 day and at 30 Hz on another day, with the stimulation strength set at 90% of the intensity that elicited pain. The motor-evoked potential amplitude of suprahyoid muscles was assessed before, immediately after, and 30 min after stimulation. Stimulations at both 20 and 30 Hz significantly increased motor-evoked potential amplitude (Pswallowing muscles, suggesting facilitation of the motor cortex related to swallowing in healthy individuals. PMID:27262135

  9. Analogous corticocortical inhibition and facilitation in ipsilateral and contralateral human motor cortex representations of the tongue.

    Science.gov (United States)

    Muellbacher, W; Boroojerdi, B; Ziemann, U; Hallett, M

    2001-11-01

    How the human brain controls activation of the ipsilateral part of midline muscles is unknown. We studied corticospinal and corticocortical network excitability of both ipsilateral and contralateral motor representations of the tongue to determine whether they are under analogous or disparate inhibitory and facilitatory corticocortical control. Motor evoked potentials (MEPs) to unilateral focal transcranial magnetic stimulation (TMS) of the tongue primary motor cortex were recorded simultaneously from the ipsilateral and contralateral lingual muscles. Single-pulse TMS was used to assess motor threshold (MT) and MEP recruitment. Paired-pulse TMS was used to study intracortical inhibition (ICI) and intracortical facilitation (ICF) at various interstimulus intervals (ISIs) between the conditioning stimulus (CS) and the test stimulus (TS), and at different CS and TS intensities, respectively. Focal TMS invariably produced MEPs in both ipsilateral and contralateral lingual muscles. MT was lower and MEP recruitment was steeper when recorded from the contralateral muscle group. ICI and ICF were identical in the ipsilateral and contralateral representations, with inhibition occurring at short ISIs (2 and 3 ms) and facilitation occurring at longer ISIs (10 and 15 ms). Moreover, changing one stimulus parameter regularly produced analogous changes in MEP size bilaterally, revealing strong linear correlations between ipsilateral and contralateral ICI and ICF (P < 0.0001). These findings indicate that the ipsilateral and contralateral representations of the tongue are under analogous inhibitory and facilitatory control, possibly by a common intracortical network. PMID:11779968

  10. Methylmercury intoxication and histochemical demonstration of NADPH-diaphorase activity in the striate cortex of adult cats

    Directory of Open Access Journals (Sweden)

    Oliveira R.B.

    1998-01-01

    Full Text Available The effects of methylmercury (MeHg on histochemical demonstration of the NADPH-diaphorase (NADPH-d activity in the striate cortex were studied in 4 adult cats. Two animals were used as control. The contaminated animals received 50 ml milk containing 0.42 µg MeHg and 100 g fish containing 0.03 µg MeHg daily for 2 months. The level of MeHg in area 17 of intoxicated animals was 3.2 µg/g wet weight brain tissue. Two cats were perfused 24 h after the last dose (group 1 and the other animals were perfused 6 months later (group 2. After microtomy, sections were processed for NADPHd histochemistry procedures using the malic enzyme method. Dendritic branch counts were performed from camera lucida drawings for control and intoxicated animals (N = 80. Average, standard deviation and Student t-test were calculated for each data group. The concentrations of mercury (Hg in milk, fish and brain tissue were measured by acid digestion of samples, followed by reduction of total Hg in the digested sample to metallic Hg using stannous chloride followed by atomic fluorescence analysis. Only group 2 revealed a reduction of the neuropil enzyme activity and morphometric analysis showed a reduction in dendritic field area and in the number of distal dendrite branches of the NADPHd neurons in the white matter (P<0.05. These results suggest that NADPHd neurons in the white matter are more vulnerable to the long-term effects of MeHg than NADPHd neurons in the gray matter.

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

    Science.gov (United States)

    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

  12. The Importance of Lateral Connections in the Parietal Cortex for Generating Motor Plans.

    Directory of Open Access Journals (Sweden)

    Derrik E Asher

    Full Text Available Substantial evidence has highlighted the significant role of associative brain areas, such as the posterior parietal cortex (PPC in transforming multimodal sensory information into motor plans. However, little is known about how different sensory information, which can have different delays or be absent, combines to produce a motor plan, such as executing a reaching movement. To address these issues, we constructed four biologically plausible network architectures to simulate PPC: 1 feedforward from sensory input to the PPC to a motor output area, 2 feedforward with the addition of an efference copy from the motor area, 3 feedforward with the addition of lateral or recurrent connectivity across PPC neurons, and 4 feedforward plus efference copy, and lateral connections. Using an evolutionary strategy, the connectivity of these network architectures was evolved to execute visually guided movements, where the target stimulus provided visual input for the entirety of each trial. The models were then tested on a memory guided motor task, where the visual target disappeared after a short duration. Sensory input to the neural networks had sensory delays consistent with results from monkey studies. We found that lateral connections within the PPC resulted in smoother movements and were necessary for accurate movements in the absence of visual input. The addition of lateral connections resulted in velocity profiles consistent with those observed in human and non-human primate visually guided studies of reaching, and allowed for smooth, rapid, and accurate movements under all conditions. In contrast, Feedforward or Feedback architectures were insufficient to overcome these challenges. Our results suggest that intrinsic lateral connections are critical for executing accurate, smooth motor plans.

  13. Early-onset motor impairment and increased accumulation of phosphorylated α-synuclein in the motor cortex of normal aging mice are ameliorated by coenzyme Q.

    Science.gov (United States)

    Takahashi, Kazuhide; Ohsawa, Ikuroh; Shirasawa, Takuji; Takahashi, Mayumi

    2016-08-01

    Brain mitochondrial function declines with age; however, the accompanying behavioral and histological alterations that are characteristic of Parkinson's disease (PD) are poorly understood. We found that the mitochondrial oxygen consumption rate (OCR) and coenzyme Q (CoQ) content were reduced in aged (15-month-old) male mice compared to those in young (6-month-old) male mice. Concomitantly, motor functions, including the rate of movement and exploratory and voluntary motor activities, were significantly reduced in the aged mice compared to the young mice. In the motor cortex of the aged mouse brain, the accumulation of α-synuclein (α-syn) phosphorylated at serine129 (Ser129) significantly increased, and the level of vesicular glutamate transporter 1 (VGluT1) decreased compared with that in the young mouse brain. The administration of exogenous water-soluble CoQ10 to aged mice via drinking water restored the mitochondrial OCR, motor function, and phosphorylated α-syn and VGluT1 levels in the motor cortex. These results suggest that early-onset motor impairment and the increased accumulation of Ser129-phosphorylated α-syn in the motor cortex are ameliorated by the exogenous administration of CoQ10. PMID:27143639

  14. Development and Maturation of Embryonic Cortical Neurons Grafted into the Damaged Adult Motor Cortex

    Science.gov (United States)

    Ballout, Nissrine; Frappé, Isabelle; Péron, Sophie; Jaber, Mohamed; Zibara, Kazem; Gaillard, Afsaneh

    2016-01-01

    Injury to the human central nervous system can lead to devastating consequences due to its poor ability to self-repair. Neural transplantation aimed at replacing lost neurons and restore functional circuitry has proven to be a promising therapeutical avenue. We previously reported in adult rodent animal models with cortical lesions that grafted fetal cortical neurons could effectively re-establish specific patterns of projections and synapses. The current study was designed to provide a detailed characterization of the spatio-temporal in vivo development of fetal cortical transplanted cells within the lesioned adult motor cortex and their corresponding axonal projections. We show here that as early as 2 weeks after grafting, cortical neuroblasts transplanted into damaged adult motor cortex developed appropriate projections to cortical and subcortical targets. Grafted cells initially exhibited characteristics of immature neurons, which then differentiated into mature neurons with appropriate cortical phenotypes where most were glutamatergic and few were GABAergic. All cortical subtypes identified with the specific markers CTIP2, Cux1, FOXP2, and Tbr1 were generated after grafting as evidenced with BrdU co-labeling. The set of data provided here is of interest as it sets biological standards for future studies aimed at replacing fetal cells with embryonic stem cells as a source of cortical neurons. PMID:27536221

  15. [The role of the motor cortex in rearrangement of the innate movement coordination in the dog].

    Science.gov (United States)

    Pavlova, O G; Mats, V N; Ponomarev, V N

    2007-01-01

    In chronical experiments in dogs the pattern of shoulder muscle recruitment was examined during the forelimb flexion by which the animal lifted and held a cup of food during eating. At the early stage of the instrumental reaction learning the forelimb lifting was performed with the anticipatory deviation of the head in up direction, when the head bent down to the foodwell the lifted forelimb lowered. Simultaneous holding of the flexed forelimb and lowered head providing food reinforcement was achieved only by learning. It was found that the forelimb lifting in the innate coordination in untrained dogs was performed with activation of m. deltoideus and m. teres major, whereas m. teres minor was active whilst the dog was standing but the muscle activity was abolished before the limb lifting. In the course of learning m. teres minor activity was changed into opposite one. In the learned coordination the limb lifting was accompanied by the activation of all three shoulder flexors. The lesion of the motor cortex in the area of the "working" forelimb, but not in other areas led to disturbance of the learned coordination and the novel pattern of the shoulder muscle activity. The data obtained led to the following conclusion: the rearrangement of the innate coordination is connected with the formation of the novel way of the forelimb lifting which pattern of muscle recruitment is provided by the motor cortex. PMID:17944105

  16. Participation of nucleus entopeduncularis in motor instrumental reflex and entopeduncular influences on motor thalamic nuclei in normal and MPTP-treated cats.

    Science.gov (United States)

    Voloshin MYa; Shevko, G N; Lukhanina, E P; Kolomiets, B P

    1993-04-01

    Activity of entopeduncular neurons was studied in chronic experiments on cats during performance of instrumental movement: pedal pressing and holding. One-hundred and twenty-four neurons were extracellularly investigated in intact animals and 81 neurons in cats treated with N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (5 mg/kg daily, intramuscularly for five days). The mean discharge frequency of nucleus entopeduncularis neurons recorded 48-72 h after the last MPTP injection increased from 12.9 +/- 1.5 to 22.1 +/- 1.4 impulses/s, but dropped to preinjection values within the next ten days. In intact animals and in MPTP-treated cats 23 and 17%, respectively, of neurons changed their activity before or during the movement performance. Along with nucleus entopeduncularis neurons that changed their activity simultaneously with instrumental movement performance, 16% of nucleus entopeduncularis nerve cells in intact cats and 12% in MPTP-treated cats responded 50-800 ms before the myogramme of working forepaw biceps was started. Excitatory responses associated with movement performance in MPTP-exposed cats were more pronounced, indicating enhancement of nucleus entopeduncularis neuronal activity in animals with injured nigrostriatal system. Since nucleus entopeduncularis neurons are inhibitory cells, the increase in their activity had to be accompanied by reinforcement of inhibitory influence on neurons in motor thalamic nuclei. In order to test this hypothesis, two groups of acute experiments were performed on ketamine-anaesthetized and myorelaxine-immobilized cats. Neuronal responses in ventral anterior and ventral lateral thalamic nuclei to nucleus entopeduncularis stimulation were investigated in normal and MPTP-treated animals in doses that were identical to those administered in chronic experiments. In intact cats, 28% of neurons responded to nucleus entopeduncularis stimulation with the latency shorter than 7 ms. In half of the inhibited neurons after the

  17. Primary motor cortex neurons classified in a postural task predict muscle activation patterns in a reaching task.

    Science.gov (United States)

    Heming, Ethan A; Lillicrap, Timothy P; Omrani, Mohsen; Herter, Troy M; Pruszynski, J Andrew; Scott, Stephen H

    2016-04-01

    Primary motor cortex (M1) activity correlates with many motor variables, making it difficult to demonstrate how it participates in motor control. We developed a two-stage process to separate the process of classifying the motor field of M1 neurons from the process of predicting the spatiotemporal patterns of its motor field during reaching. We tested our approach with a neural network model that controlled a two-joint arm to show the statistical relationship between network connectivity and neural activity across different motor tasks. In rhesus monkeys, M1 neurons classified by this method showed preferred reaching directions similar to their associated muscle groups. Importantly, the neural population signals predicted the spatiotemporal dynamics of their associated muscle groups, although a subgroup of atypical neurons reversed their directional preference, suggesting a selective role in antagonist control. These results highlight that M1 provides important details on the spatiotemporal patterns of muscle activity during motor skills such as reaching. PMID:26843605

  18. Modulation of Dendritic Spine Remodeling in the Motor Cortex Following Spinal Cord Injury: Effects of Environmental Enrichment and Combinatorial Treatment with Transplants and Neurotrophin-3

    OpenAIRE

    Kim, Byung G.; Dai, Hai-Ning; MCATEE, MARIETTA; Bregman, Barbara S.

    2008-01-01

    Incomplete spinal cord injury (SCI) elicits structural plasticity of the spared motor system, including the motor cortex, which may underlie some of the spontaneous recovery of motor function seen after injury. Promoting structural plasticity may become an important component of future strategies to improve functional outcomes. We have recently observed dynamic changes in the density and morphology of dendritic spines in the motor cortex following SCI. The present study sought to test whether...

  19. Encoding of temporal information by timing, rate, and place in cat auditory cortex.

    Directory of Open Access Journals (Sweden)

    Kazuo Imaizumi

    Full Text Available A central goal in auditory neuroscience is to understand the neural coding of species-specific communication and human speech sounds. Low-rate repetitive sounds are elemental features of communication sounds, and core auditory cortical regions have been implicated in processing these information-bearing elements. Repetitive sounds could be encoded by at least three neural response properties: 1 the event-locked spike-timing precision, 2 the mean firing rate, and 3 the interspike interval (ISI. To determine how well these response aspects capture information about the repetition rate stimulus, we measured local group responses of cortical neurons in cat anterior auditory field (AAF to click trains and calculated their mutual information based on these different codes. ISIs of the multiunit responses carried substantially higher information about low repetition rates than either spike-timing precision or firing rate. Combining firing rate and ISI codes was synergistic and captured modestly more repetition information. Spatial distribution analyses showed distinct local clustering properties for each encoding scheme for repetition information indicative of a place code. Diversity in local processing emphasis and distribution of different repetition rate codes across AAF may give rise to concurrent feed-forward processing streams that contribute differently to higher-order sound analysis.

  20. Parallel Cortical Networks Formed by Modular Organization of Primary Motor Cortex Outputs.

    Science.gov (United States)

    Hamadjida, Adjia; Dea, Melvin; Deffeyes, Joan; Quessy, Stephan; Dancause, Numa

    2016-07-11

    In primates, the refinement of motor behaviors, in particular hand use, is associated with the establishment of more direct projections from primary motor cortex (M1) onto cervical motoneurons [1, 2] and the appearance of additional premotor and sensory cortical areas [3]. All of these areas have reciprocal connections with M1 [4-7]. Thus, during the evolution of the sensorimotor network, the number of interlocutors with which M1 interacts has tremendously increased. It is not clear how these additional interconnections are organized in relation to one another within the hand representation of M1. This is important because the organization of connections between M1 and phylogenetically newer and specialized cortical areas is likely to be key to the increased repertoire of hand movements in primates. In cebus monkeys, we used injections of retrograde tracers into the hand representation of different cortical areas of the sensorimotor network (ventral and dorsal premotor areas [PMv and PMd], supplementary motor area [SMA], and posterior parietal cortex [area 5]), and we analyzed the pattern of labeled neurons within the hand representation of M1. Instead of being uniformly dispersed across M1, neurons sending projections to each distant cortical area were largely segregated in different subregions of M1. These data support the view that primates split the cortical real estate of M1 into modules, each preferentially interconnected with a particular cortical area within the sensorimotor network. This modular organization could sustain parallel processing of interactions with multiple specialized cortical areas to increase the behavioral repertoire of the hand. PMID:27322001

  1. Comparison of LFP-Based and Spike-Based Spectro-Temporal Receptive Fields and Cross-Correlation in Cat Primary Auditory Cortex

    OpenAIRE

    Eggermont, Jos J.; Munguia, Raymundo; Pienkowski, Martin; Shaw, Greg

    2011-01-01

    Multi-electrode array recordings of spike and local field potential (LFP) activity were made from primary auditory cortex of 12 normal hearing, ketamine-anesthetized cats. We evaluated 259 spectro-temporal receptive fields (STRFs) and 492 frequency-tuning curves (FTCs) based on LFPs and spikes simultaneously recorded on the same electrode. We compared their characteristic frequency (CF) gradients and their cross-correlation distances. The CF gradient for spike-based FTCs was about twice that ...

  2. Synchrony between orientation-selective neurons is modulated during adaptation-induced plasticity in cat visual cortex

    Directory of Open Access Journals (Sweden)

    Shumikhina Svetlana

    2008-07-01

    Full Text Available Abstract Background Visual neurons respond essentially to luminance variations occurring within their receptive fields. In primary visual cortex, each neuron is a filter for stimulus features such as orientation, motion direction and velocity, with the appropriate combination of features eliciting maximal firing rate. Temporal correlation of spike trains was proposed as a potential code for linking the neuronal responses evoked by various features of a same object. In the present study, synchrony strength was measured between cells following an adaptation protocol (prolonged exposure to a non-preferred stimulus which induce plasticity of neurons' orientation preference. Results Multi-unit activity from area 17 of anesthetized adult cats was recorded. Single cells were sorted out and (1 orientation tuning curves were measured before and following 12 min adaptation and 60 min after adaptation (2 pairwise synchrony was measured by an index that was normalized in relation to the cells' firing rate. We first observed that the prolonged presentation of a non-preferred stimulus produces attractive (58% and repulsive (42% shifts of cell's tuning curves. It follows that the adaptation-induced plasticity leads to changes in preferred orientation difference, i.e. increase or decrease in tuning properties between neurons. We report here that, after adaptation, the neuron pairs that shared closer tuning properties display a significant increase of synchronization. Recovery from adaptation was accompanied by a return to the initial synchrony level. Conclusion We conclude that synchrony reflects the similarity in neurons' response properties, and varies accordingly when these properties change.

  3. Motor learning and modulation of prefrontal cortex: an fNIRS assessment

    Science.gov (United States)

    Ono, Yumie; Noah, Jack Adam; Zhang, Xian; Nomoto, Yasunori; Suzuki, Tatsuya; Shimada, Sotaro; Tachibana, Atsumichi; Bronner, Shaw; Hirsch, Joy

    2015-12-01

    Objective. Prefrontal hemodynamic responses are observed during performance of motor tasks. Using a dance video game (DVG), a complex motor task that requires temporally accurate footsteps with given visual and auditory cues, we investigated whether 20 h of DVG training modified hemodynamic responses of the prefrontal cortex in six healthy young adults. Approach. Fronto-temporal activity during actual DVG play was measured using functional near-infrared spectroscopy (fNIRS) pre- and post-training. To evaluate the training-induced changes in the time-courses of fNIRS signals, we employed a regression analysis using the task-specific template fNIRS signals that were generated from alternate well-trained and/or novice DVG players. The HRF was also separately incorporated as a template to construct an alternate regression model. Change in coefficients for template functions at pre- and post- training were determined and compared among different models. Main results. Training significantly increased the motor performance using the number of temporally accurate steps in the DVG as criteria. The mean oxygenated hemoglobin (ΔoxyHb) waveform changed from an activation above baseline pattern to that of a below baseline pattern. Participants showed significantly decreased coefficients for regressors of the ΔoxyHb response of novice players and HRF. The model using ΔoxyHb responses from both well-trained and novice players of DVG as templates showed the best fit for the ΔoxyHb responses of the participants at both pre- and post-training when analyzed with Akaike information criteria. Significance. These results suggest that the coefficients for the template ΔoxyHb responses of the novice players are sensitive indicators of motor learning during the initial stage of training and thus clinically useful to determine the improvement in motor performance when patients are engaged in a specific rehabilitation program.

  4. Stimulation over primary motor cortex during action observation impairs effector recognition.

    Science.gov (United States)

    Naish, Katherine R; Barnes, Brittany; Obhi, Sukhvinder S

    2016-04-01

    Recent work suggests that motor cortical processing during action observation plays a role in later recognition of the object involved in the action. Here, we investigated whether recognition of the effector making an action is also impaired when transcranial magnetic stimulation (TMS) - thought to interfere with normal cortical activity - is applied over the primary motor cortex (M1) during action observation. In two experiments, single-pulse TMS was delivered over the hand area of M1 while participants watched short clips of hand actions. Participants were then asked whether an image (experiment 1) or a video (experiment 2) of a hand presented later in the trial was the same or different to the hand in the preceding video. In Experiment 1, we found that participants' ability to recognise static images of hands was significantly impaired when TMS was delivered over M1 during action observation, compared to when no TMS was delivered, or when stimulation was applied over the vertex. Conversely, stimulation over M1 did not affect recognition of dot configurations, or recognition of hands that were previously presented as static images (rather than action movie clips) with no object. In Experiment 2, we found that effector recognition was impaired when stimulation was applied part way through (300ms) and at the end (500ms) of the action observation period, indicating that 200ms of action-viewing following stimulation was not long enough to form a new representation that could be used for later recognition. The findings of both experiments suggest that interfering with cortical motor activity during action observation impairs subsequent recognition of the effector involved in the action, which complements previous findings of motor system involvement in object memory. This work provides some of the first evidence that motor processing during action observation is involved in forming representations of the effector that are useful beyond the action observation period

  5. Influence of position and stimulation parameters on intracortical inhibition and facilitation in human tongue motor cortex

    DEFF Research Database (Denmark)

    Kothari, Mohit; Svensson, Peter; Nielsen, Jørgen Feldbæk;

    2014-01-01

    tongue motor cortex and motor evoked potentials (MEPs) were recorded from contralateral tongue muscles. In study 1, single pulse and three ppTMS ISIs: 2, 10, 15 ms were applied 8 times each in three blocks (TS: 120%, 140% and 160% of resting motor threshold (rMT); CS: 80% of rMT) in two different body......Paired-pulse transcranial magnetic stimulation (ppTMS) can be used to assess short-interval intracortical inhibitory (SICI) and facilitatory (ICF) networks. Many methodological parameters may however influence the outcome. The aim of the study was to examine the influence of body positions (recline...... positions (recline and supine) randomly. In study 2, single pulse and four ppTMS ISIs: 2, 2.5, 3, 3.5 ms were applied 8 times each in randomized order in two blocks (CS: 70% and 80% of rMT; TS: 120% of rMT). There was a significant effect of body position (P=0.049), TS intensities (P<0.001) and ISIs (P<0...

  6. Enhancement of motor coordination by applying high frequency repetitive TMS on the sensory cortex.

    Science.gov (United States)

    Choi, Eun-Hi; Yoo, Woo-Kyoung; Ohn, Suk Hoon; Ahn, SeungHo; Kim, Han Jun; Jung, Kwang-Ik

    2016-06-01

    The sensory function plays an important role for successful motor performance. We investigated the modulating effects of high frequency repetitive transcranial magnetic stimulation (rTMS) on sensory discrimination and motor coordination. Twenty healthy participants were assigned into two random groups; the real- and sham-rTMS group. Total of 900 rTMS pulses at a frequency of 10Hz (stimulus intensity of 90% RMT) were given over deltoid representational areas of the somatosensory cortex. Sensory discrimination ability was evaluated using two-point discrimination test. Motor coordination was measured by the latency difference between the synchronized contraction of deltoid and abductor pollicis brevis muscles before and after rTMS. The sensory discrimination was significantly increased only in the deltoid area and the difference in the latency of synchronized contraction of two muscles was significantly shortened after real-rTMS compared sham condition, which had tendency of negative correlation following real-rTMS condition. The results of this study demonstrated rTMS-induced enhancement of sensorimotor integration, which may contribute to develop effective therapeutic strategies for rehabilitation of various sensorimotor disorders in the clinical setting. PMID:26978587

  7. Diversity of Layer 5 Projection Neurons in the Mouse Motor Cortex

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    Manfred J Oswald

    2013-10-01

    Full Text Available In the primary motor cortex (M1, layer 5 projection neurons signal directly to distant motor structures to drive movement. Despite their pivotal position and acknowledged diversity these neurons are traditionally separated into broad commissural and corticofugal types, and until now no attempt has been made at resolving the basis for their diversity. We therefore probed the electrophysiological and morphological properties of retrogradely labelled M1 corticospinal (CSp, corticothalamic (CTh, and commissural projecting corticostriatal (CStr and corticocortical (CC neurons. An unsupervised cluster analysis established at least four phenotypes with additional differences between lumbar and cervical projecting CSp neurons. Distinguishing parameters included the action potential (AP waveform, firing behaviour, the hyperpolarisation-activated sag potential, sublayer position, and soma and dendrite size. CTh neurons differed from CSp neurons in showing spike frequency acceleration and a greater sag potential. CStr neurons had the lowest AP amplitude and maximum rise rate of all neurons. Temperature influenced spike train behaviour in corticofugal neurons. At 26 ºC CTh neurons fired bursts of APs more often than CSp neurons, but at 36 ºC both groups fired regular APs. Our findings provide reliable phenotypic fingerprints to identify distinct M1 projection neuron classes as a tool to understand their unique contributions to motor function.

  8. Motor cortex and hippocampus are the two main cortical targets in LGI1-antibody encephalitis.

    Science.gov (United States)

    Navarro, Vincent; Kas, Aurélie; Apartis, Emmanuelle; Chami, Linda; Rogemond, Véronique; Levy, Pierre; Psimaras, Dimitri; Habert, Marie-Odile; Baulac, Michel; Delattre, Jean-Yves; Honnorat, Jérome

    2016-04-01

    Encephalitis associated with antibodies against leucine-rich glioma-inactivated 1 (LGI1) protein is increasingly recognized as an auto-immune disorder associated with characteristic tonic-dystonic seizures. The cortical or subcortical origin of these motor events is not clear. Some patients also present with different epileptic seizures and with cognitive impairment. The frequency of these features and their timing during the natural history of this encephalitis have not been fully described. We therefore reviewed data from 34 patients harbouring antibodies against LGI1 protein (21-81 years, median age 64) referred to the French Reference Centre for Neurological Paraneoplastic Syndrome. Three types of evidence suggested tonic-dystonic seizures were of cortical origin: (i) a slow, unilateral, frontal electroencephalographic wave, of duration ∼580 ms and amplitude ∼71 µV, preceded the contralateral tonic-dystonic seizures in simultaneous electroencephalographic and myographic records from seven of seven patients tested; (ii) 18-Fluorodeoxyglucose imaging revealed a strong hypermetabolism in primary motor cortex, controlateral to the affected limb, during encephalitis for five patients tested, as compared with data from the same patients after remission or from 16 control subjects; and (iii) features of polymyographic records of tonic-dystonic seizure events pointed to a cortical origin. Myoclonic patterns with brief, rhythmic bursts were present in three of five patients tested and a premyoclonic potential was identified in the cortex of one patient. Initially during encephalitis, 11 of 34 patients exhibited tonic-dystonic seizures (32%). Distinct epileptic syndromes were evident in 13 patients (38%). They were typically simple, focal seizures from the temporal lobe, consisting of vegetative symptoms or fear. At later stages, 22 of 32 patients displayed tonic-dystonic seizures (68%) and 29 patients presented frequent seizures (91%) including status epilepticus

  9. Functional reorganization of human motor cortex after unaffected side C7 nerve root transposition

    International Nuclear Information System (INIS)

    Objective: To assess the characteristics of neuronal activity in human motor cortex after the seventh cervical nerve root transposition of the unaffected side by using functional MRI (fMRI). Methods: Thirteen patients who accepted the seventh cervical nerve root transposition of the unaffected side, due to total brachial plexus traction injury diagnosed by manifestation and operation, were examined retrospectively by using fMRI. 10 patients were injured on the left side and 3 on the right side. According to functional recovery of the affected hand, all subjects can be divided into 2 groups. The patients of the first group could not move the affected hand voluntarily. The patients of the second group could move the affected hand self-determined. 12 healthy volunteer's were also involved in this study as control. The fMRI examinations were performed by using echo-planer BOLD sequence. Then the SPM 99 software was used for post-processing. Results: The neuronal activation induced by the movement of both unaffected and affected upper' limb was seen in the contralateral PMC in all patients; Neuronal activation in the ipsilateral PMC evoked by movement of the unaffected extremity was seen in 10 cases, and induced by movement of the affected limb was seen in 7 cases. In the first group, the sharp of clusters in the contralateral PMC resulted by movement of the unaffected extremity showed normal in 9 eases, the average size of clusters resulted by the unaffected hand was 3159 (voxel), and resulted by the unaffected shoulder was 1746(voxel). The sharp of clusters in the contralateral PMC resulted by the affected shoulder or hand were revealed enlargement in 6 cases of each. In the second group, 1 case showed neuronal activation induced by movement of the affected limb in the PMC in both sides of motor cortex, and 2 cases showed neuronal activation in the contralateral PMC. Conclusions: Peripheral nerve injury was able to cause changes of motor cortex in human brain

  10. Analysis of neural activity in human motor cortex -- Towards brain machine interface system

    Science.gov (United States)

    Secundo, Lavi

    The discovery of directional tuned neurons in the primary motor cortex has advanced motor research in several domains. For instance, in the area of brain machine interface (BMI), researchers have exploited the robust characteristic of tuned motor neurons to allow monkeys to learn control of various machines. In the first chapter of this work we examine whether this phenomena can be observed using the less invasive method of recording electrocorticographic signals (ECoG) from the surface of a human's brain. Our findings reveal that individual ECoG channels contain complex movement information about the neuronal population. While some ECoG channels are tuned to hand movement direction (direction specific channels), others are associated to movement but do not contain information regarding movement direction (non-direction specific channels). More specifically, directionality can vary temporally and by frequency within one channel. In addition, a handful of channels contain no significant information regarding movement at all. These findings strongly suggest that directional and non-directional regions of cortex can be identified with ECoG and provide solutions to decoding movement at the signal resolution provided by ECoG. In the second chapter we examine the influence of movement context on movement reconstruction accuracy. We recorded neuronal signals recorded from electro-corticography (ECoG) during performance of cued- and self-initiated movements. ECoG signals were used to train a reconstruction algorithm to reconstruct continuous hand movement. We found that both cued- and self-initiated movements could be reconstructed with similar accuracy from the ECoG data. However, while an algorithm trained on the cued task could reconstruct performance on a subsequent cued trial, it failed to reconstruct self-initiated arm movement. The same task-specificity was observed when the algorithm was trained with self-initiated movement data and tested on the cued task. Thus

  11. Role of the primary motor cortex in the early boost in performance following mental imagery training.

    Directory of Open Access Journals (Sweden)

    Ursula Debarnot

    Full Text Available Recently, it has been suggested that the primary motor cortex (M1 plays a critical role in implementing the fast and transient post-training phase of motor skill consolidation, known to yield an early boost in performance. Whether a comparable early boost in performance occurs following motor imagery (MIM training is still unknown. To address this issue, two groups of subjects learned a finger tapping sequence either by MIM or physical practice (PP. In both groups, performance increased significantly in the post-training phase when compared with the pre-training phase and further increased after a 30 min resting period, indicating that both MIM and PP trainings were equally efficient and induced an early boost in motor performance. This conclusion was corroborated by the results of an additional control group. In a second experiment, we then investigated the causal role of M1 in implementing the early boost process resulting from MIM training. To do so, we inhibited M1 by applying a continuous theta-burst stimulation (cTBS in healthy volunteers just after they learnt, by MIM, the same finger-tapping task as in Experiment #1. As a control, cTBS was applied over the vertex of subjects who underwent the same experiment. We found that cTBS applied over M1 selectively abolished the early boost process subsequent to MIM training. Altogether, the present study provides evidence that MIM practice induces an early boost in performance and demonstrates that M1 is causally involved in this process. These findings further divulge some degree of behavioral and neuronal similitude between MIM and PP.

  12. Motor cortex stimulation for neuropathic pain syndromes: a case series experience.

    Science.gov (United States)

    Buchanan, Robert J; Darrow, David; Monsivais, Daniel; Nadasdy, Zoltan; Gjini, Klevest

    2014-06-18

    Neuropathic pain is a chronic condition lacking effective management and responding poorly to standard treatment protocols. Motor cortex stimulation has emerged as a new and promising therapeutic tool with outcomes potentially affected by the specific causes and location. In this study we report a series of eight cases in the neurosurgery practice of one of the authors (R.J.B.), including neuropathic pain syndromes of trigeminal or thalamic origin with or without anesthesia dolorosa. Pain relief was evaluated on the basis of comparison of Visual Analog scores at baseline and at 3 months after surgery. In addition, we assessed differences in pain relief outcomes between cases with trigeminal neuralgia and thalamic stroke, as well as cases with or without anesthesia dolorosa (i.e. pain with numbness of the affected area). Visual Analog Scale scores showed a statistically significant decrease of 4.19 (P=0.002) at 3 months follow-up compared with baseline. Pain relief levels in four of five patients in the subgroup with facial pain were higher than 50%, and none of the patients in the subgroup with thalamic and phantom limb pain showed such a good outcome. Furthermore, we found larger pain relief levels in facial pain conditions with versus without anesthesia dolorosa. These results point to utility of motor cortex stimulation in relieving neuropathic pain, as well as better outcomes for patients with facial pain and anesthesia dolorosa. Future studies should incorporate methods to noninvasively trial those patients who may benefit from surgical implantation to predict the outcomes and maximize their negative predictive value. PMID:24780896

  13. Motor and parietal cortex stimulation for phantom limb pain and sensations.

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    Bolognini, Nadia; Olgiati, Elena; Maravita, Angelo; Ferraro, Francesco; Fregni, Felipe

    2013-08-01

    Limb amputation may lead to chronic painful sensations referred to the absent limb, ie phantom limb pain (PLP), which is likely subtended by maladaptive plasticity. The present study investigated whether transcranial direct current stimulation (tDCS), a noninvasive technique of brain stimulation that can modulate neuroplasticity, can reduce PLP. In 2 double-blind, sham-controlled experiments in subjects with unilateral lower or upper limb amputation, we measured the effects of a single session of tDCS (2 mA, 15 min) of the primary motor cortex (M1) and of the posterior parietal cortex (PPC) on PLP, stump pain, nonpainful phantom limb sensations and telescoping. Anodal tDCS of M1 induced a selective short-lasting decrease of PLP, whereas cathodal tDCS of PPC induced a selective short-lasting decrease of nonpainful phantom sensations; stump pain and telescoping were not affected by parietal or by motor tDCS. These findings demonstrate that painful and nonpainful phantom limb sensations are dissociable phenomena. PLP is associated primarily with cortical excitability shifts in the sensorimotor network; increasing excitability in this system by anodal tDCS has an antalgic effect on PLP. Conversely, nonpainful phantom sensations are associated to a hyperexcitation of PPC that can be normalized by cathodal tDCS. This evidence highlights the relationship between the level of excitability of different cortical areas, which underpins maladaptive plasticity following limb amputation and the phenomenology of phantom limb, and it opens up new opportunities for the use of tDCS in the treatment of PLP. PMID:23707312

  14. The involvement of the left motor cortex in learning of a novel action word lexicon.

    Science.gov (United States)

    Liuzzi, Gianpiero; Freundlieb, Nils; Ridder, Volker; Hoppe, Julia; Heise, Kirstin; Zimerman, Maximo; Dobel, Christian; Enriquez-Geppert, Stefanie; Gerloff, Christian; Zwitserlood, Pienie; Hummel, Friedhelm C

    2010-10-12

    Current theoretical positions assume that action-related word meanings are established by functional connections between perisylvian language areas and the motor cortex (MC) according to Hebb's associative learning principle. To test this assumption, we probed the functional relevance of the left MC for learning of a novel action word vocabulary by disturbing neural plasticity in the MC with transcranial direct current stimulation (tDCS). In combination with tDCS, subjects learned a novel vocabulary of 76 concrete, body-related actions by means of an associative learning paradigm. Compared with a control condition with "sham" stimulation, cathodal tDCS reduced success rates in vocabulary acquisition, as shown by tests of novel action word translation into the native language. The analysis of learning behavior revealed a specific effect of cathodal tDCS on the ability to associatively couple actions with novel words. In contrast, we did not find these effects in control experiments, when tDCS was applied to the prefrontal cortex or when subjects learned object-related words. The present study lends direct evidence to the proposition that the left MC is causally involved in the acquisition of novel action-related words. PMID:20888226

  15. The Contribution of Primary Motor Cortex Is Essential for Probabilistic Implicit Sequence Learning: Evidence from Theta Burst Magnetic Stimulation

    Science.gov (United States)

    Wilkinson, Leonora; Teo, James T.; Obeso, Ignacio; Rothwell, John C.; Jahanshahi, Marjan

    2010-01-01

    Theta burst transcranial magnetic stimulation (TBS) is considered to produce plastic changes in human motor cortex. Here, we examined the inhibitory and excitatory effects of TBS on implicit sequence learning using a probabilistic serial reaction time paradigm. We investigated the involvement of several cortical regions associated with implicit…

  16. Ryk controls remapping of motor cortex during functional recovery after spinal cord injury.

    Science.gov (United States)

    Hollis, Edmund R; Ishiko, Nao; Yu, Ting; Lu, Chin-Chun; Haimovich, Ariela; Tolentino, Kristine; Richman, Alisha; Tury, Anna; Wang, Shih-Hsiu; Pessian, Maysam; Jo, Euna; Kolodkin, Alex; Zou, Yimin

    2016-05-01

    Limited functional recovery can be achieved through rehabilitation after incomplete spinal cord injury. Eliminating the function of a repulsive Wnt receptor, Ryk, in mice and rats by either conditional knockout in the motor cortex or monoclonal antibody infusion resulted in increased corticospinal axon collateral branches with presynaptic puncta in the spinal cord and enhanced recovery of forelimb reaching and grasping function following a cervical dorsal column lesion. Using optical stimulation, we observed that motor cortical output maps underwent massive changes after injury and that hindlimb cortical areas were recruited to control the forelimb over time. Furthermore, a greater cortical area was dedicated to controlling the forelimb in Ryk conditional knockout mice than in controls (wild-type or heterozygotes). In the absence of weekly task-specific training, recruitment of ectopic cortical areas was greatly reduced and there was no significant functional recovery even in Ryk conditional knockout mice. Our study provides evidence that maximal circuit reorganization and functional recovery can be achieved by combining molecular manipulation and targeted rehabilitation. PMID:27065364

  17. The role of the murine motor cortex in action duration and order

    Directory of Open Access Journals (Sweden)

    Henry H Yin

    2009-10-01

    Full Text Available This study examined the contributions of the primary and secondary motor cortices (M1 and M2 to action differentiation and sequencing in mice. In Experiment 1, mice with excitotoxic lesions of M1 and M2 and sham controls learned to emit lever presses exceeding a criterion duration to earn food rewards. Duration differentiation obeys Weber’s law—i.e. the spread of the distribution is proportional to the average duration. M1 or M2 lesions did not affect differentiation of press durations. Experiment 2 studied the effects of the same lesions on the learning of a simple sequence consisting of two lever presses, one distal, and the other proximal, to the reward. M2 lesions impaired the acquisition and reversal of this sequence. M1 lesions, by contrast, had no effect on acquisition but impaired sequence reversal. Moreover, duration of the first press in a sequence was on average twice as long as that of the second press, though this ratio was not affected by motor cortex lesions. Together these results offer a first glimpse into the cortical substrates of instrumental differentiation in mice.

  18. Inducing homeostatic-like plasticity in human motor cortex through converging corticocortical inputs

    DEFF Research Database (Denmark)

    Pötter-Nerger, Monika; Fischer, Sarah; Mastroeni, Claudia;

    2009-01-01

    (LTD)-like or long-term potentiation (LTP)-like plasticity in left M1(HAND) through different afferents. We hypothesized that the left M1(HAND) would integrate LTP- and LTD-like plasticity in a homeostatic fashion. In ten healthy volunteers, low-intensity repetitive transcranial magnetic stimulation (r......TMS) of the left dorsal premotor cortex (PMD) was first applied to produce an LTP-like increase (5 Hz rTMS) or LTD-like decrease (1 Hz rTMS) in corticospinal excitability in left M1(HAND) via premotor-to-motor inputs. Following PMD rTMS, paired-associative stimulation (PAS) was applied to the right median...... nerve and left M1(HAND) to induce spike-time-dependent plasticity in sensory-to-motor inputs to left M1(HAND). We adjusted the interstimulus interval to the N20 latency of the median nerve somatosensory-evoked cortical potential to produce an LTP-like increase (PAS(N20+2ms)) or an LTD-like decrease (PAS...

  19. Motor association cortex activity in Parkinson's disease. A functional MRI study

    International Nuclear Information System (INIS)

    The purpose of this study was to examine the activation of motor association cortex using functional magnetic resonance imaging (fMRI) in patients with Parkinson's disease (PD) and control subjects during performed hand movements. There were 26 patients with PD (12 patients with Hoehn and Yahr stage I-II, 14 patients with stage III) and 8 control subjects. Functional imaging was performed using a 1.5 tesla MRI system equipped with a single-shot, echo-planar pulse sequence. The significant signal changes were observed within the primary sensorimotor area, the supplementary motor area (SMA), and the parietal association area in both PD and control subjects. In PD subjects, the SMA was less activated than in control subjects; there were significant differences in the number of pixels activated in SMA between control and Yahr III group (p<0.01), and between Yahr I-II and Yahr III group (p<0.01). Our results demonstrated that movement related cerebral activity in the SMA is reduced in PD subjects, consistent with previously published data using other methods. It is well known from anatomical studies that one of the major cortical outputs of the basal ganglia is the SMA. This may explain the hypoactivation of the SMA in PD. Studies using fMRI provide a promising method not only for localizing cortical activation related to voluntary movements but also for investigating pathophysiology of movement disorders. (author)

  20. Motor association cortex activity in Parkinson`s disease. A functional MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Yukiko [Yamaguchi Univ., Ube (Japan). School of Medicine

    1998-08-01

    The purpose of this study was to examine the activation of motor association cortex using functional magnetic resonance imaging (fMRI) in patients with Parkinson`s disease (PD) and control subjects during performed hand movements. There were 26 patients with PD (12 patients with Hoehn and Yahr stage I-II, 14 patients with stage III) and 8 control subjects. Functional imaging was performed using a 1.5 tesla MRI system equipped with a single-shot, echo-planar pulse sequence. The significant signal changes were observed within the primary sensorimotor area, the supplementary motor area (SMA), and the parietal association area in both PD and control subjects. In PD subjects, the SMA was less activated than in control subjects; there were significant differences in the number of pixels activated in SMA between control and Yahr III group (p<0.01), and between Yahr I-II and Yahr III group (p<0.01). Our results demonstrated that movement related cerebral activity in the SMA is reduced in PD subjects, consistent with previously published data using other methods. It is well known from anatomical studies that one of the major cortical outputs of the basal ganglia is the SMA. This may explain the hypoactivation of the SMA in PD. Studies using fMRI provide a promising method not only for localizing cortical activation related to voluntary movements but also for investigating pathophysiology of movement disorders. (author)

  1. Coupling brain-machine interfaces with cortical stimulation for brain-state dependent stimulation: enhancing motor cortex excitability for neurorehabilitation

    Directory of Open Access Journals (Sweden)

    Alireza Gharabaghi

    2014-03-01

    Full Text Available Motor recovery after stroke is an unsolved challenge despite intensive rehabilitation training programs. Brain stimulation techniques have been explored in addition to traditional rehabilitation training to increase the excitability of the stimulated motor cortex. This modulation of cortical excitability augments the response to afferent input during motor exercises, thereby enhancing skilled motor learning by long-term potentiation-like plasticity. Recent approaches examined brain stimulation applied concurrently with voluntary movements to induce more specific use-dependent neural plasticity during motor training for neurorehabilitation. Unfortunately, such approaches are not applicable for the many severely affected stroke patients lacking residual hand function. These patients require novel activity-dependent stimulation paradigms based on intrinsic brain activity. Here, we report on such brain state-dependent stimulation (BSDS combined with haptic feedback provided by a robotic hand orthosis. Transcranial magnetic stimulation of the motor cortex and haptic feedback to the hand were controlled by sensorimotor desynchronization during motor-imagery and applied within a brain-machine interface environment in one healthy subject and one patient with severe hand paresis in the chronic phase after stroke. BSDS significantly increased the excitability of the stimulated motor cortex in both healthy and post-stroke conditions, an effect not observed in non-BSDS protocols. This feasibility study suggests that closing the loop between intrinsic brain state, cortical stimulation and haptic feedback provides a novel neurorehabilitation strategy for stroke patients lacking residual hand function, a proposal that warrants further investigation in a larger cohort of stroke patients.

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

    Science.gov (United States)

    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.

  3. Modulation of Training by Single-Session Transcranial Direct Current Stimulation to the Intact Motor Cortex Enhances Motor Skill Acquisition of the Paretic Hand

    Science.gov (United States)

    Zimerman, Máximo; Heise, Kirstin F.; Hoppe, Julia; Cohen, Leonardo G.; Gerloff, Christian; Hummel, Friedhelm C.

    2016-01-01

    Background and Purpose Mechanisms of skill learning are paramount components for stroke recovery. Recent noninvasive brain stimulation studies demonstrated that decreasing activity in the contralesional motor cortex might be beneficial, providing transient functional improvements after stroke. The more crucial question, however, is whether this intervention can also enhance the acquisition of complex motor tasks, yielding longer-lasting functional improvements. In the present study, we tested the capacity of cathodal transcranial direct current stimulation (tDCS) applied over the contralesional motor cortex during training to enhance the acquisition and retention of complex sequential finger movements of the paretic hand. Method Twelve well-recovered chronic patients with subcortical stroke attended 2 training sessions during which either cathodal tDCS or a sham intervention were applied to the contralesional motor cortex in a double-blind, crossover design. Two different motor sequences, matched for their degree of complexity, were tested in a counterbalanced order during as well as 90 minutes and 24 hours after the intervention. Potential underlying mechanisms were evaluated with transcranial magnetic stimulation. Results tDCS facilitated the acquisition of a new motor skill compared with sham stimulation (P=0.04) yielding better task retention results. A significant correlation was observed between the tDCS-induced improvement during training and the tDCS-induced changes of intracortical inhibition (R2=0.63). Conclusions These results indicate that tDCS is a promising tool to improve not only motor behavior, but also procedural learning. They further underline the potential of noninvasive brain stimulation as an adjuvant treatment for long-term recovery, at least in patients with mild functional impairment after stroke. PMID:22618381

  4. Local field potentials in primate motor cortex encode grasp kinetic parameters.

    Science.gov (United States)

    Milekovic, Tomislav; Truccolo, Wilson; Grün, Sonja; Riehle, Alexa; Brochier, Thomas

    2015-07-01

    Reach and grasp kinematics are known to be encoded in the spiking activity of neuronal ensembles and in local field potentials (LFPs) recorded from primate motor cortex during movement planning and execution. However, little is known, especially in LFPs, about the encoding of kinetic parameters, such as forces exerted on the object during the same actions. We implanted two monkeys with microelectrode arrays in the motor cortical areas MI and PMd to investigate encoding of grasp-related parameters in motor cortical LFPs during planning and execution of reach-and-grasp movements. We identified three components of the LFP that modulated during grasps corresponding to low (0.3-7Hz), intermediate (~10-~40Hz) and high (~80-250Hz) frequency bands. We show that all three components can be used to classify not only grip types but also object loads during planning and execution of a grasping movement. In addition, we demonstrate that all three components recorded during planning or execution can be used to continuously decode finger pressure forces and hand position related to the grasping movement. Low and high frequency components provide similar classification and decoding accuracies, which were substantially higher than those obtained from the intermediate frequency component. Our results demonstrate that intended reach and grasp kinetic parameters are encoded in multiple LFP bands during both movement planning and execution. These findings also suggest that the LFP is a reliable signal for the control of parameters related to object load and applied pressure forces in brain-machine interfaces. PMID:25869861

  5. Excitability of the motor cortex in de novo patients with celiac disease.

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    Giovanni Pennisi

    Full Text Available INTRODUCTION: Celiac disease (CD may initially present as a neurological disorder or may be complicated by neurological changes. To date, neurophysiological studies aiming to an objective evaluation of the potential central nervous system involvement in CD are lacking. OBJECTIVE: To assess the profile of cortical excitability to Transcranial Magnetic Stimulation (TMS in a group of de novo CD patients. MATERIALS AND METHODS: Twenty CD patients underwent a screening for cognitive and neuropsychiatric symptoms by means of the Mini Mental State Examination and the Structured Clinical Interview for DSM-IV Axis I Disorders, respectively. Instrumental exams, including electroencephalography and brain computed tomography, were also performed. Cortico-spinal excitability was assessed by means of single and paired-pulse TMS using the first dorsal interosseus muscle of the dominant hand. TMS measures consisted of resting motor threshold, motor evoked potentials, cortical silent period (CSP, intracortical inhibition (ICI and facilitation (ICF. None of the CD was on gluten-free diet. A group of 20 age-matched healthy controls was used for comparisons. RESULTS: CD showed a significantly shorter CSP (78.0 vs 125.0 ms, p<0.025, a reduced ICI (0.3 vs 0.2, p<0.045 and an enhanced ICF (1.1 vs 0.7, p<0.042 compared to controls. A dysthymic disorder was identified in five patients. The effect size between dysthymic and non-dysthymic CD patients indicated a low probability of interference with the CSP (Cohen's d -0.414, ICI (-0.278 and ICF (-0.292 measurements. CONCLUSION: A pattern of cortical excitability characterized by "disinhibition" and "hyperfacilitation" was found in CD patients. Immune system dysregulation might play a central role in triggering changes of the motor cortex excitability.

  6. Motoneuron properties during motor inhibition produced by microinjection of carbachol into the pontine reticular formation of the decerebrate cat.

    Science.gov (United States)

    Morales, F R; Engelhardt, J K; Soja, P J; Pereda, A E; Chase, M H

    1987-04-01

    It is well established that cholinergic agonists, when injected into the pontine reticular formation in cats, produce a generalized suppression of motor activity (1, 3, 6, 14, 18, 27, 33, 50). The responsible neuronal mechanisms were explored by measuring ventral root activity, the amplitude of the Ia-monosynaptic reflex, and the basic electrophysiological properties of hindlimb motoneurons before and after carbachol was microinjected into the pontine reticular formation of decerebrate cats. Intrapontine microinjections of carbachol (0.25-1.0 microliter, 16 mg/ml) resulted in the tonic suppression of ventral root activity and a decrease in the amplitude of the Ia-monosynaptic reflex. An analysis of intracellular records from lumbar motoneurons during the suppression of motor activity induced by carbachol revealed a considerable decrease in input resistance and membrane time constant as well as a reduction in motoneuron excitability, as evidenced by a nearly twofold increase in rheobase. Discrete inhibitory postsynaptic potentials were also observed following carbachol administration. The changes in motoneuron properties (rheobase, input resistance, and membrane time constant), as well as the development of discrete inhibitory postsynaptic potentials, indicate that spinal cord motoneurons were postsynaptically inhibited following the pontine administration of carbachol. In addition, the inhibitory processes that arose after carbachol administration in the decerebrate cat were remarkably similar to those that are present during active sleep in the chronic cat. These findings suggest that the microinjection of carbachol into the pontine reticular formation activates the same brain stem-spinal cord system that is responsible for the postsynaptic inhibition of alpha-motoneurons that occurs during active sleep. PMID:3585456

  7. A quantitative comparison of the hemispheric, areal, and laminar origins of sensory and motor cortical projections to the superior colliculus of the cat.

    Science.gov (United States)

    Butler, Blake E; Chabot, Nicole; Lomber, Stephen G

    2016-09-01

    The superior colliculus (SC) is a midbrain structure central to orienting behaviors. The organization of descending projections from sensory cortices to the SC has garnered much attention; however, rarely have projections from multiple modalities been quantified and contrasted, allowing for meaningful conclusions within a single species. Here, we examine corticotectal projections from visual, auditory, somatosensory, motor, and limbic cortices via retrograde pathway tracers injected throughout the superficial and deep layers of the cat SC. As anticipated, the majority of cortical inputs to the SC originate in the visual cortex. In fact, each field implicated in visual orienting behavior makes a substantial projection. Conversely, only one area of the auditory orienting system, the auditory field of the anterior ectosylvian sulcus (fAES), and no area involved in somatosensory orienting, shows significant corticotectal inputs. Although small relative to visual inputs, the projection from the fAES is of particular interest, as it represents the only bilateral cortical input to the SC. This detailed, quantitative study allows for comparison across modalities in an animal that serves as a useful model for both auditory and visual perception. Moreover, the differences in patterns of corticotectal projections between modalities inform the ways in which orienting systems are modulated by cortical feedback. J. Comp. Neurol. 524:2623-2642, 2016. © 2016 Wiley Periodicals, Inc. PMID:26850989

  8. Electrophysiological properties of lumbar motoneurons in the alpha-chloralose-anesthetized cat during carbachol-induced motor inhibition.

    Science.gov (United States)

    Xi, M C; Liu, R H; Yamuy, J; Morales, F R; Chase, M H

    1997-07-01

    The present study was undertaken 1) to examine the neuronal mechanisms responsible for the inhibition of spinal cord motoneurons that occurs in alpha-chloralose-anesthetized cats following the microinjection of carbachol into the nucleus pontis oralis (NPO), and 2) to determine whether the inhibitory mechanisms are the same as those that are responsible for the postsynaptic inhibition of motoneurons that is present during naturally occurring active sleep. Accordingly, the basic electrophysiological properties of lumbar motoneurons were examined, with the use of intracellular recording techniques, in cats anesthetized with alpha-chloralose and compared with those present during naturally occurring active sleep. The intrapontine administration of carbachol resulted in a sustained reduction in the amplitude of the spinal cord Ia monosynaptic reflex. Discrete large-amplitude inhibitory postsynaptic potentials (IPSPs), which are only present during the state of active sleep in the chronic cat, were also observed in high-gain recordings from lumbar motoneurons after the injection of carbachol. During carbachol-induced motor inhibition, lumbar motoneurons exhibited a statistically significant decrease in input resistance, membrane time constant and a reduction in the amplitude of the action potential's afterhyperpolarization. In addition, there was a statistically significant increase in rheobase and in the delay between the initial-segment (IS) and somadendritic (SD) portions of the action potential (IS-SD delay). There was a significant increase in the mean motoneuron resting membrane potential (i.e., hyperpolarization). The preceding changes in the electrophysiological properties of motoneurons, as well as the development of discrete IPSPs, indicate that lumbar motoneurons are postsynaptically inhibited after the intrapontine administration of carbachol in cats that are anesthetized with alpha-chloralose. These changes in the electrophysiological properties of lumbar

  9. Primary sensory and motor cortex excitability are co-modulated in response to peripheral electrical nerve stimulation.

    Directory of Open Access Journals (Sweden)

    Siobhan M Schabrun

    Full Text Available Peripheral electrical stimulation (PES is a common clinical technique known to induce changes in corticomotor excitability; PES applied to induce a tetanic motor contraction increases, and PES at sub-motor threshold (sensory intensities decreases, corticomotor excitability. Understanding of the mechanisms underlying these opposite changes in corticomotor excitability remains elusive. Modulation of primary sensory cortex (S1 excitability could underlie altered corticomotor excitability with PES. Here we examined whether changes in primary sensory (S1 and motor (M1 cortex excitability follow the same time-course when PES is applied using identical stimulus parameters. Corticomotor excitability was measured using transcranial magnetic stimulation (TMS and sensory cortex excitability using somatosensory evoked potentials (SEPs before and after 30 min of PES to right abductor pollicis brevis (APB. Two PES paradigms were tested in separate sessions; PES sufficient to induce a tetanic motor contraction (30-50 Hz; strong motor intensity and PES at sub motor-threshold intensity (100 Hz. PES applied to induce strong activation of APB increased the size of the N(20-P(25 component, thought to reflect sensory processing at cortical level, and increased corticomotor excitability. PES at sensory intensity decreased the size of the P25-N33 component and reduced corticomotor excitability. A positive correlation was observed between the changes in amplitude of the cortical SEP components and corticomotor excitability following sensory and motor PES. Sensory PES also increased the sub-cortical P(14-N(20 SEP component. These findings provide evidence that PES results in co-modulation of S1 and M1 excitability, possibly due to cortico-cortical projections between S1 and M1. This mechanism may underpin changes in corticomotor excitability in response to afferent input generated by PES.

  10. Age-dependent changes in the midsized neurofilament subunit in sensory-motor systems of the cat brainstem: an immunocytochemical study.

    Science.gov (United States)

    Zhang, J H; Sampogna, S; Morales, F R; Chase, M H

    2000-05-01

    This study documents age-related changes in the immunoreactivity of the medium-molecular weight subunit of neurofilaments in sensory and motor neurons in the brainstem of the cat. In old age, there was a clear decrease in immunoreactivity in the following brainstem sensory and motor nuclei: sensory trigeminal, gracile, cuneate, and facial motor. Only a few neuronal perikarya and dendrites were labeled in these nuclei in old cats; moreover, when present, the labeling was weak. In contrast, in adult cats, these nuclei contained intensely stained neuronal perikarya and dendrites. In other sensory and motor nuclei of the brainstem, there was an obvious age-related increase in the immunoreactivity of the medium-molecular weight subunit of neurofilaments in the perikarya. Despite different patterns of age-related alterations in immunoreactivity within perikarya and dendrites in distinct brainstem regions, most sensory and motor axons in old cats were smaller than those in adult cats. A decrease in the medium-molecular weight neurofilament subunit in the dendrites may be the basis for the dendritic atrophy that has been shown to occur in sensory nuclei in old animals. The decrease in axonal size is likely to be one of the causes of the decrease in axonal conduction velocity, in these neurons, that was reported in our previous studies. PMID:10819310

  11. The mode of synaptic activation of pyramidal neurons in the cat primary somatosensory cortex: an intracellular HRP study.

    Science.gov (United States)

    Yamamoto, T; Samejima, A; Oka, H

    1990-01-01

    A total of 141 pyramidal neurons in the cat primary somatosensory cortex (SI) were recorded intracellularly under Nembutal anesthesia (7 in layer II, 43 in layer III, 8 in layer IV, 58 in layer V and 25 in layer VI). Most neurons were identified by intracellular staining with HRP, though some layer V pyramidal neurons were identified only electrophysiologically with antidromic activation of medullary pyramid (PT) or pontine nuclear (PN) stimulation. Excitatory synaptic potentials (EPSPs) were analyzed with stimulation of the superficial radial nerve (SR), the ventral posterolateral nucleus (VPL) in the thalamus and the thalamic radiation (WM). The pyramidal neurons in layers III and IV received EPSPs at the shortest latency: 9.1 +/- 2.1 ms (Mean +/- S.D.) for SR and 1.6 +/- 0.7 ms for VPL stimulation. Layer II pyramidal neurons also responded at a short latency to VPL stimulation (1.7 +/- 0.5 ms), though their mean latencies for SR-induced EPSPs were relatively longer (10.6 +/- 1.9 ms). The mean latencies were much longer in layers V and VI pyramidal neurons (10.2 +/- 2.4 ms and 2.9 +/- 1.5 ms in layer V pyramidal neurons and 9.9 +/- 2.5 ms and 2.8 +/- 1.6 ms in layer VI pyramidal ones, respectively for SR and VPL stimulation). The comparison of the latencies between VPL and WM stimulation indicates that most layer III-IV pyramidal neurons and some pyramidal cells in layers II, V and VI received monosynaptic inputs from VPL. These findings are consistent with morphological data on the laminar distribution of thalamocortical fibers, i.e., thalamocortical fibers terminate mainly in the deeper part of layers III and IV with some collaterals in layers V, VI and II-I. The time-sequences of the latencies of VPL-EPSPs indicate that corticocortical and/or transcallosal neurons (pyramidal neurons in layers II and III) fire first and are followed by firing of the output neurons projecting to the subcortical structures (pyramidal neurons in layers V and VI). PMID:2358022

  12. Asymmetric activation of the primary motor cortex during observation of a mirror reflection of a hand.

    Directory of Open Access Journals (Sweden)

    Wataru Tominaga

    Full Text Available Mirror therapy is an effective technique for pain relief and motor function recovery. It has been demonstrated that magnetic 20-Hz activity is induced in the primary motor cortex (M1 after median nerve stimulation and that the amount of the stimulus-induced 20-Hz activity is decreased when the M1 is activated. In the present study, we investigated how the image or the mirror reflection of a hand holding a pencil modulates the stimulus-induced 20-Hz activity in the M1. Neuromagnetic brain activity was recorded from 13 healthy right-handed subjects while they were either viewing directly their hand holding a pencil or viewing a mirror reflection of their hand holding a pencil. The 20-Hz activity in the left or the right M1 was examined after the right or the left median nerve stimulation, respectively, and the suppression of the stimulus-induced 20-Hz in the M1 by viewing directly one hand holding a pencil or by viewing the mirror image of the hand holding a pencil was assumed to indicate the activation of the M1. The results indicated that the M1 innervating the dominant hand was suppressed either by viewing directly the dominant hand holding a pencil or by viewing the mirror image of the non-dominant hand holding a pencil. On the other hand, the M1 innervating the non-dominant hand was activated by viewing the mirror image of the dominant hand holding a pencil, but was not activated by viewing directly the non-dominant hand holding a pencil. The M1 innervating either the dominant or the non-dominant hand, however, was not activated by viewing the hand on the side ipsilateral to the M1 examined or the mirror image of the hand on the side contralateral to the M1 exaimined. Such activation of the M1 might induce some therapeutic effects of mirror therapy.

  13. Different strategies do not moderate primary motor cortex involvement in mental rotation: a TMS study

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    Koeneke Susan

    2007-08-01

    Full Text Available Abstract Background Regions of the dorsal visual stream are known to play an essential role during the process of mental rotation. The functional role of the primary motor cortex (M1 in mental rotation is however less clear. It has been suggested that the strategy used to mentally rotate objects determines M1 involvement. Based on the strategy hypothesis that distinguishes between an internal and an external strategy, our study was designed to specifically test the relation between strategy and M1 activity. Methods Twenty-two subjects were asked to participate in a standard mental rotation task. We used specific picture stimuli that were supposed to trigger either the internal (e.g. pictures of hands or tools or the external strategy (e.g. pictures of houses or abstract figures. The strategy hypothesis predicts an involvement of M1 only in case of stimuli triggering the internal strategy (imagine grasping and rotating the object by oneself. Single-pulse Transcranial Magnetic Stimulation (TMS was employed to quantify M1 activity during task performance by measuring Motor Evoked Potentials (MEPs at the right hand muscle. Results Contrary to the strategy hypothesis, we found no interaction between stimulus category and corticospinal excitability. Instead, corticospinal excitability was generally increased compared with a resting baseline although subjects indicated more frequent use of the external strategy for all object categories. Conclusion This finding suggests that M1 involvement is not exclusively linked with the use of the internal strategy but rather directly with the process of mental rotation. Alternatively, our results might support the hypothesis that M1 is active due to a 'spill-over' effect from adjacent brain regions.

  14. Abnormal motor cortex excitability during linguistic tasks in adductor-type spasmodic dysphonia.

    Science.gov (United States)

    Suppa, A; Marsili, L; Giovannelli, F; Di Stasio, F; Rocchi, L; Upadhyay, N; Ruoppolo, G; Cincotta, M; Berardelli, A

    2015-08-01

    In healthy subjects (HS), transcranial magnetic stimulation (TMS) applied during 'linguistic' tasks discloses excitability changes in the dominant hemisphere primary motor cortex (M1). We investigated 'linguistic' task-related cortical excitability modulation in patients with adductor-type spasmodic dysphonia (ASD), a speech-related focal dystonia. We studied 10 ASD patients and 10 HS. Speech examination included voice cepstral analysis. We investigated the dominant/non-dominant M1 excitability at baseline, during 'linguistic' (reading aloud/silent reading/producing simple phonation) and 'non-linguistic' tasks (looking at non-letter strings/producing oral movements). Motor evoked potentials (MEPs) were recorded from the contralateral hand muscles. We measured the cortical silent period (CSP) length and tested MEPs in HS and patients performing the 'linguistic' tasks with different voice intensities. We also examined MEPs in HS and ASD during hand-related 'action-verb' observation. Patients were studied under and not-under botulinum neurotoxin-type A (BoNT-A). In HS, TMS over the dominant M1 elicited larger MEPs during 'reading aloud' than during the other 'linguistic'/'non-linguistic' tasks. Conversely, in ASD, TMS over the dominant M1 elicited increased-amplitude MEPs during 'reading aloud' and 'syllabic phonation' tasks. CSP length was shorter in ASD than in HS and remained unchanged in both groups performing 'linguistic'/'non-linguistic' tasks. In HS and ASD, 'linguistic' task-related excitability changes were present regardless of the different voice intensities. During hand-related 'action-verb' observation, MEPs decreased in HS, whereas in ASD they increased. In ASD, BoNT-A improved speech, as demonstrated by cepstral analysis and restored the TMS abnormalities. ASD reflects dominant hemisphere excitability changes related to 'linguistic' tasks; BoNT-A returns these excitability changes to normal. PMID:26061279

  15. Sentential context modulates the involvement of the motor cortex in action language processing: An fMRI study

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    Karen D.I. Schuil

    2013-04-01

    Full Text Available Theories of embodied cognition propose that language comprehension is based on perceptual and motor processes. More specifically, it is hypothesized that neurons processing verbs describing bodily actions, and those that process the corresponding physical actions, fire simultaneously during action verb learning. Thus the concept and motor activation become strongly linked. According to this view, the language-induced activation of the neural substrates for action is automatic. By contrast, a moderate view of embodied cognition proposes that activation of these motor regions is modulated by context. In recent studies it was found that action verbs in literal sentences activate the motor system, while mixed results were observed for action verbs in nonliteral sentences. Thus, whether the recruitment of motor regions is automatic or context dependent remains a question. We investigated functional magnetic resonance imaging activation in response to nonliteral and literal sentences including arm and leg related actions. The sentence structure was such that the action verb was the last word in the subordinate clause. Thus, the constraining context was presented well before the verb. Region of interest analyses showed that action verbs in literal context engage the motor regions to a greater extent than nonliteral action verbs. There was no evidence for a semantic somatotopic organization of the motor cortex. Taken together, these results indicate that during comprehension, the degree to which motor regions are recruited is context dependent, supporting the weak view of embodied cognition.

  16. Motor cortex tDCS does not improve strength performance in healthy subjects

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    Rafael Montenegro

    2015-06-01

    Full Text Available The influence of transcranial direct current stimulation (tDCS upon maximal strength performance in exercises recruiting large muscle mass has not been established in healthy populations. The purpose of this study was to investigate whether anodal tDCS was able to increase the performance during maximal strength exercise (MSEX in healthy subjects. Fourteen volunteers (age: 26 ± 4 yrs performed two MSEX after anodal or sham tDCS (2mA; 20min prior MSEX, involving knee extensors and flexors in concentric isokinetic muscle actions of the dominant limb (3 sets of 10 repetitions. The electrical muscle activity (sEMG of four recruited muscles was recorded during MSEX. Anodal tDCS was not able to improve force production (i.e., total work and peak torque, fatigue resistance, or electromyographic activity during MSEX when compared to sham condition. In conclusion, anodal tDCS applied upon the contralateral motor cortex was not capable of increasing the strength performance of knee extensors and flexors in young healthy subjects.

  17. Sizes and distributions of intrinsic neurons incorporating tritiated GABA in monkey sensory-motor cortex

    International Nuclear Information System (INIS)

    Neurons accumulating [3H]gamma-aminobutyric acid (GABA) were identified autoradiographically in frozen and plastic sections after injection of the material in the monkey somatic sensory (areas 3, 1, and 2), motor (area 4), and parietal (area 5) cortex following intravenous administration of a GABA transaminase inhibitor, amino-oxyacetic acid. Two general forms of labeled cells are recognized: those with large diameter (15- to 20-micrometer) somata, probably corresponding to the basket cells of Golgi studies, and those with small diameter (6- to 12-micrometer) somata, probably corresponding to several other types. The sizes and laminar distributions of labeled cells in the cytoarchitectonic fields of the first somatic sensory are (SI) are similar. In these areas, the greatest concentrations of labeled cells are in layer II, in layer IV, and in the superficial stratum of layer IV. In area 5, there are many fewer labeled cells in layer IV. In area 4, the labeled cells are larger and distributed more homogeneously, though there are fewer in layer VI. The large labeled cell type is concentrated in layers III and V of all areas. The smaller labeled types are found in all other layers, including layer I. In layer IV, they form approximately 40% of the total small-celled neuronal population

  18. Prediction of hand trajectory from electrocorticography signals in primary motor cortex.

    Directory of Open Access Journals (Sweden)

    Chao Chen

    Full Text Available Due to their potential as a control modality in brain-machine interfaces, electrocorticography (ECoG has received much focus in recent years. Studies using ECoG have come out with success in such endeavors as classification of arm movements and natural grasp types, regression of arm trajectories in two and three dimensions, estimation of muscle activity time series and so on. However, there still remains considerable work to be done before a high performance ECoG-based neural prosthetic can be realized. In this study, we proposed an algorithm to decode hand trajectory from 15 and 32 channel ECoG signals recorded from primary motor cortex (M1 in two primates. To determine the most effective areas for prediction, we applied two electrode selection methods, one based on position relative to the central sulcus (CS and another based on the electrodes' individual prediction performance. The best coefficients of determination for decoding hand trajectory in the two monkeys were 0.4815 ± 0.0167 and 0.7780 ± 0.0164. Performance results from individual ECoG electrodes showed that those with higher performance were concentrated at the lateral areas and areas close to the CS. The results of prediction according with different numbers of electrodes based on proposed methods were also shown and discussed. These results also suggest that superior decoding performance can be achieved from a group of effective ECoG signals rather than an entire ECoG array.

  19. Primary motor cortex of the parkinsonian monkey: Altered neuronal responses to muscle stretch

    Directory of Open Access Journals (Sweden)

    Benjamin Pasquereau

    2013-11-01

    Full Text Available Exaggeration of the long-latency stretch reflex (LLSR is a characteristic neurophysiologic feature of Parkinson’s disease (PD that contributes to parkinsonian rigidity. To explore one frequently-hypothesized mechanism, we studied the effects of fast muscle stretches on neuronal activity in the macaque primary motor cortex (M1 before and after the induction of parkinsonism by unilateral administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP. We compared results from the general population of M1 neurons and two antidromically-identified subpopulations: distant-projecting pyramidal-tract type neurons (PTNs and intra-telecenphalic-type corticostriatal neurons (CSNs. Rapid rotations of elbow or wrist joints evoked short-latency responses in 62% of arm-related M1 neurons. As in PD, the late electromyographic responses that constitute the LLSR were enhanced following MPTP. This was accompanied by a shortening of M1 neuronal response latencies and a degradation of directional selectivity, but surprisingly, no increase in single unit response magnitudes. The results suggest that parkinsonism alters the timing and specificity of M1 responses to muscle stretch. Observation of an exaggerated LLSR with no change in the magnitude of proprioceptive responses in M1 is consistent with the idea that the increase in LLSR gain that contributes to parkinsonian rigidity is localized to the spinal cord.

  20. Motor cortex rTMS improves dexterity in relapsing-remitting and secondary progressive multiple sclerosis.

    Science.gov (United States)

    Elzamarany, Eman; Afifi, Lamia; El-Fayoumy, Neveen M; Salah, Husam; Nada, Mona

    2016-06-01

    The motor cortex (MC) receives an excitatory input from the cerebellum which is reduced in patients with cerebellar lesions. High-frequency repetitive transcranial magnetic stimulation (rTMS) induces cortical facilitation which can counteract the reduced cerebellar drive to the MC. Our study included 24 relapsing-remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS) patients with dysmetria. The patients were divided into two groups: Group A received two sessions of real MC rTMS and Group B received one session of real rTMS and one session of sham rTMS. Ten healthy volunteers formed group C. Evaluation was carried out using the nine-hole pegboard task and the cerebellar functional system score (FSS) of the expanded disability status scale (EDSS). Group A patients showed a significant improvement in the time required to finish the pegboard task (P = 0.002) and in their cerebellar FSS (P = 0.000) directly after the second session and 1 month later. The RRMS patients showed more improvement than the SPMS patients. Group B patients did not show any improvement in the pegboard task or the cerebellar FSS. These results indicate that MC rTMS can be a promising option in treating both RRMS or SPMS patients with cerebellar impairment and that its effect can be long-lasting. PMID:26358951

  1. The changes of regional cerebral blood flow: successful pain relief of intractable CRPS type II patients by motor cortex stimulation

    International Nuclear Information System (INIS)

    Authors report the effectiveness of MCS in extraordinarily extended pain due to intractable CRPS type II and rCBF study result for mechanism of pain control by MCS. A 43-year-old male presented severe spontaneous burning pain in his left hand and forearm and allodynia over the left arm and left hemibody. Authors planned MCS as a neuromodulation therapy for this intractable peripheral neuropathic pain patient because further neurodestructive procedure did not work anymore and have a potential risk of further aggrevation of neuopathic pain. We performed baseline and stimulation brain perfusion SPECT using 20 mCi of Tc-99m ECD. The baseline CBD studies were done with stimulator 'off' state and stimulation studies were done after stimulator 'on' with satisfactory pain relief. For the stimulation study, the radioisotope was injected immediately after pain-relief and the images were taken about 50 minutes after injection of radioisotope. In resting rCBF in the patient was compared with normal control datas, we found significant increase in rCBF in the bilateral prefrontal cortex, right dorsolateral prefrontal cortex, right superior temporal gyrus, left temporooccipital area. When rCBF datas obtained after alleviation of pain with stimulator 'on' . there were significant increase in rCBF in bilateral prefrontal cortex and left temporoocipital area. After subtraction of ECD SPECT, we found significant increase in rCBF in the right premotor and supplementary motor cortex left sensorimotor cortex, right cingulated cortex, right posterior insular cortex, right anterior limb of internal capsule. left orbitofrontal cortex and right pyramidal tract in cerebral peduncle. Authors report exellent pain control by MCS in a case of severe CRPS type II with hemibody involvement and regional cerebral blood flow changes according to successful pain control

  2. [Role of different projection areas of the motor cortex in reorganization of the innate head-forelimb coordination in dogs].

    Science.gov (United States)

    Pavlova, O G; Mats, V N

    2005-01-01

    Dogs were trained to perform the forelimb tonic flexion in order to lift a cup with meat from a bottom of the foodwell and hold it during eating with the head bent down to the cup. It is known that conditioning of the instrumental reaction is based on reorganization of the innate head-forelimb coordination into the opposite one. In untrained dogs, the forelimb flexion is accompanied by the anticipatory lifting of the head bent down to the foodwell. The following lowering of the head leads to an extension of the flexed forelimb. Tonic forelimb flexion is possible if the head is in the up position. Simultaneous holding of the flexed forelimb and lowered head providing food reinforcement is achieved only by learning. It was shown earlier that the lesion of the motor cortex contralateral to the "working" forelimb led to a prolonged disturbance of the elaborated coordination and reappearance of the innate coordination. In the present work we studied the influence of local lesions of the projection areas in the motor cortex, such as a "working" forelimb area, bilateral representation of the neck, and the medial part of the motor cortex, on the learned instrumental feeding reaction. It was found that only the lesion of the forelimb but not neck projection led to a disturbance of the learned head-forelimb movement coordination. PMID:16396488

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

    Science.gov (United States)

    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. PMID:25301352

  4. Synaptic Basis for Cross-modal Plasticity: Enhanced Supragranular Dendritic Spine Density in Anterior Ectosylvian Auditory Cortex of the Early Deaf Cat.

    Science.gov (United States)

    Clemo, H Ruth; Lomber, Stephen G; Meredith, M Alex

    2016-04-01

    In the cat, the auditory field of the anterior ectosylvian sulcus (FAES) is sensitive to auditory cues and its deactivation leads to orienting deficits toward acoustic, but not visual, stimuli. However, in early deaf cats, FAES activity shifts to the visual modality and its deactivation blocks orienting toward visual stimuli. Thus, as in other auditory cortices, hearing loss leads to cross-modal plasticity in the FAES. However, the synaptic basis for cross-modal plasticity is unknown. Therefore, the present study examined the effect of early deafness on the density, distribution, and size of dendritic spines in the FAES. Young cats were ototoxically deafened and raised until adulthood when they (and hearing controls) were euthanized, the cortex stained using Golgi-Cox, and FAES neurons examined using light microscopy. FAES dendritic spine density averaged 0.85 spines/μm in hearing animals, but was significantly higher (0.95 spines/μm) in the early deaf. Size distributions and increased spine density were evident specifically on apical dendrites of supragranular neurons. In separate tracer experiments, cross-modal cortical projections were shown to terminate predominantly within the supragranular layers of the FAES. This distributional correspondence between projection terminals and dendritic spine changes indicates that cross-modal plasticity is synaptically based within the supragranular layers of the early deaf FAES. PMID:25274986

  5. Movement representation in the primary motor cortex and its contribution to generalizable EMG predictions.

    Science.gov (United States)

    Oby, Emily R; Ethier, Christian; Miller, Lee E

    2013-02-01

    It is well known that discharge of neurons in the primary motor cortex (M1) depends on end-point force and limb posture. However, the details of these relations remain unresolved. With the development of brain-machine interfaces (BMIs), these issues have taken on practical as well as theoretical importance. We examined how the M1 encodes movement by comparing single-neuron and electromyographic (EMG) preferred directions (PDs) and by predicting force and EMGs from multiple neurons recorded during an isometric wrist task. Monkeys moved a cursor from a central target to one of eight peripheral targets by exerting force about the wrist while the forearm was held in one of two postures. We fit tuning curves to both EMG and M1 activity measured during the hold period, from which we computed both PDs and the change in PD between forearm postures (ΔPD). We found a unimodal distribution of these ΔPDs, the majority of which were intermediate between the typical muscle response and an unchanging, extrinsic coordinate system. We also discovered that while most neuron-to-EMG predictions generalized well across forearm postures, end-point force measured in extrinsic coordinates did not. The lack of force generalization was due to musculoskeletal changes with posture. Our results show that the dynamics of most of the recorded M1 signals are similar to those of muscle activity and imply that a BMI designed to drive an actuator with dynamics like those of muscles might be more robust and easier to learn than a BMI that commands forces or movements in external coordinates. PMID:23155172

  6. Simultaneous Reconstruction of Continuous Hand Movements from Primary Motor and Posterior Parietal Cortex

    Science.gov (United States)

    Philip, Benjamin A.; Rao, Naveen; Donoghue, John P.

    2013-01-01

    Primary motor cortex (MI) and parietal area PE both participate in cortical control of reaching actions, but few studies have been able to directly compare the form of kinematic encoding in the two areas simultaneously during hand tracking movements. To directly compare kinematic coding properties in these two areas under identical behavioral conditions, we recorded simultaneously from two chronically implanted multielectrode arrays in areas MI and PE (or areas 2/5) during performance of a continuous manual tracking task (CMTT). Monkeys manually pursued a continuously moving target that followed a series of straight-line movement segments, arranged in a sequence where the direction (but not length) of the upcoming segment varied unpredictably as each new segment appeared. Based on recordings from populations of MI (31–143 units) and PE (22–87 units), we compared hand position and velocity reconstructions based on linear filters. We successfully reconstructed hand position and velocity from area PE (mean r2 = 0.751 for position reconstruction, r2 = 0.614 for velocity), demonstrating trajectory reconstruction from each area. Combing these populations provided no reconstruction improvements, suggesting that kinematic representations in MI and PE encode overlapping hand movement information, rather than complementary or unique representations. These overlapping representations may reflect the areas’ common engagement in a sensorimotor feedback loop for error signals and movement goals, as required by a task with continuous, time-evolving demands and feedback. The similarity of information in both areas suggests that either area might provide a suitable target to obtain control signals for brain computer interface applications. PMID:23274645

  7. Timing-dependent modulation of the posterior parietal cortex-primary motor cortex pathway by sensorimotor training

    DEFF Research Database (Denmark)

    Karabanov, Anke; Jin, Seung-Hyun; Joutsen, Atte;

    2012-01-01

    performed a sensorimotor training task that involved tapping the index finger in synchrony to a rhythmic sequence. To explore differences in training modality, one group (n = 8) learned by visual and the other (n = 9) by auditory stimuli. Transcranial magnetic stimulation (TMS) was used to assess PPC-M1......-motor interactions are activated during early sensorimotor training when sensory information has to be integrated into a coherent movement plan. Once the sequence is encoded and movements become automatized, PPC-M1 connectivity returns to baseline....

  8. Timing-dependent modulation of the posterior parietal cortex-primary motor cortex pathway by sensorimotor training

    DEFF Research Database (Denmark)

    Karabanov, Anke Ninija; Jin, Seung-Hyun; Joutsen, Atte;

    2012-01-01

    performed a sensorimotor training task that involved tapping the index finger in synchrony to a rhythmic sequence. To explore differences in training modality, one group (n = 8) learned by visual and the other (n = 9) by auditory stimuli. Transcranial magnetic stimulation (TMS) was used to assess PPC-M1......-motor interactions are activated during early sensorimotor training when sensory information has to be integrated into a coherent movement plan. Once the sequence is encoded and movements become automatized, PPC-M1 connectivity returns to baseline...

  9. Motor function improvement with mirror therapy in stroke patients: a CAT

    Directory of Open Access Journals (Sweden)

    Raúl Aguilera Eguía

    2013-12-01

    Full Text Available Introduction Stroke comprises several conditions characterized by sudden, non-convulsive loss of neurological function. A large percentage of individuals who survive stroke will have limb motor sequelae. Aim To assess the validity and applicability of the results regarding the effectiveness of mirror therapy in patients with stroke and answer the following question: In stroke subjects, can mirror therapy improve motor function? Method We analyzed the article "Mirror therapy for improving motor function after stroke," Cochrane Systematic Review [Thieme 20121]. Results Mirror therapy may increase motor function between the second and sixth week of intervention, with a standardized mean difference (SMD of 0.61 (95% CI 0.22-1.00. Conclusion Despite methodological limitations of the primary studies included in the systematic review, we found that mirror therapy is a reasonable adjunct to standard therapy by physiotherapists.

  10. Motor function improvement with mirror therapy in stroke patients: a CAT

    OpenAIRE

    Raúl Aguilera Eguía; Edson Zafra Santos; Alejandro Ibacache Palma

    2013-01-01

    Introduction Stroke comprises several conditions characterized by sudden, non-convulsive loss of neurological function. A large percentage of individuals who survive stroke will have limb motor sequelae. Aim To assess the validity and applicability of the results regarding the effectiveness of mirror therapy in patients with stroke and answer the following question: In stroke subjects, can mirror therapy improve motor function? Method We analyzed the article "Mirror therapy f...

  11. Effects of Swimming Exercise on Limbic and Motor Cortex Neurogenesis in the Kainate-Lesion Model of Temporal Lobe Epilepsy

    Science.gov (United States)

    Gorantla, Vasavi R.; Sirigiri, Amulya; Volkova, Yulia A.; Millis, Richard M.

    2016-01-01

    Temporal lobe epilepsy (TLE) is a common neurological disease and antiseizure medication is often inadequate for preventing apoptotic cell death. Aerobic swimming exercise (EX) augments neurogenesis in rats when initiated immediately in the postictal period. This study tests the hypothesis that aerobic exercise also augments neurogenesis over the long term. Male Wistar rats (age of 4 months) were subjected to chemical lesioning using KA and to an EX intervention consisting of a 30 d period of daily swimming for 15 min, in one experiment immediately after KA lesioning (immediate exposure) and in a second experiment after a 60 d period of normal activity (delayed exposure). Morphometric counting of neuron numbers (NN) and dendritic branch points and intersections (DDBPI) was performed in the CA1, CA3, and dentate regions of hippocampus, in basolateral nucleus of amygdala, and in several areas of motor cortex. EX increased NN and DDBPI in the normal control and the KA-lesioned rats in all four limbic and motor cortex areas studied, after both immediate and 60 d delayed exposures to exercise. These findings suggest that, after temporal lobe epileptic seizures in rats, swimming exercise may improve neural plasticity in areas of the brain involved with emotional regulation and motor coordination, even if the exercise treatment is delayed. PMID:27313873

  12. Observation of activation status of motor-related cortex of patients with acute ischemic stroke through functional magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Ziqian Chen; Hui Xiao; Ping Ni; Gennian Qian; Shangwen Xu; Xizhang Yang; Youqiang Ye; Jinhua Chen; Biyun Zhang

    2006-01-01

    BACKGROUND: About more than three fourth of patients with stroke have motor dysfunction at different degrees, especially hand motor dysfunction. Functional magnetic resonance imaging (fMRI) provides very reliable visible evidence for studying central mechanism of motor dysfunction after stroke, and has guiding and applicable value for clinical therapy.OBJECTIVE: To observe the activation of motor-related cortex of patients with acute ischemic stroke with functional magnetic resonance imaging, and analyze the relationship between brain function reconstruction and motor restoration after stroke.DESIGN: A contrast observation.SETTING: Medical Imaging Center, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS: Nine patients with acute ischemic stroke who suffered from motor dysfunction and received the treatment in the Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA between August and December 2005 were recruited, serving as experimental group. The involved patients including 5 male and 4 female, aged 16 to 87 years, all met the diagnostic criteria of cerebrovascular disease revised by The Fourth National Conference on Cerebrovascular Disease, mainly presenting paralysis in clinic, and underwent fMRI. Another 9 right handed persons matched in age and gender who simultaneously received healthy body examination were recruited, serving as control group. All the subjects were informed of the detected items.METHODS: ①Muscular strength of patients of the experimental group was evaluated according to Brunnstrom grading muscular strength (Grade Ⅰ -Ⅵ). ② Passive finger to finger motion was used as the mission (alternate style of quiescence, left hand motion and quiescence, right hand motion was repeated 3 times, serving as 1 sequence, 20 s per block and 20 s time interval. The whole process of scanning was 260 s), and subjects of 2 groups were given Bold-fMRI examination with GE1.5T double gradient 16-channel

  13. Transcranial Direct Current Stimulation over the Medial Prefrontal Cortex and Left Primary Motor Cortex (mPFC-lPMC) Affects Subjective Beauty but Not Ugliness.

    Science.gov (United States)

    Nakamura, Koyo; Kawabata, Hideaki

    2015-01-01

    Neuroaesthetics has been searching for the neural bases of the subjective experience of beauty. It has been demonstrated that neural activities in the medial prefrontal cortex (mPFC) and the left primary motor cortex (lPMC) correlate with the subjective experience of beauty. Although beauty and ugliness seem to be semantically and conceptually opposite, it is still unknown whether these two evaluations represent extreme opposites in unitary or bivariate dimensions. In this study, we applied transcranial direct current stimulation (tDCS) to examine whether non-invasive brain stimulation modulates two types of esthetic evaluation; evaluating beauty and ugliness. Participants rated the subjective beauty and ugliness of abstract paintings before and after the application of tDCS. Application of cathodal tDCS over the mPFC with anode electrode over the lPMC, which induced temporal inhibition of neural excitability of the mPFC, led to a decrease in beauty ratings but not ugliness ratings. There were no changes in ratings of both beauty and ugliness when applying anodal tDCS or sham stimulation over the mPFC. Results from our experiment indicate that the mPFC and the lPMC have a causal role in generating the subjective experience of beauty, with beauty and ugliness evaluations constituting two distinct dimensions. PMID:26696865

  14. Transcranial direct current stimulation over the medial prefrontal cortex and left primary motor cortex (mPFC-lPMC affects subjective beauty but not ugliness

    Directory of Open Access Journals (Sweden)

    Koyo eNakamura

    2015-12-01

    Full Text Available Neuroaesthetics has been searching for the neural bases of the subjective experience of beauty. It has been demonstrated that neural activities in the medial prefrontal cortex (mPFC and the left primary motor cortex (lPMC correlate with the subjective experience of beauty. Although beauty and ugliness seem to be semantically and conceptually opposite, it is still unknown whether these two evaluations represent extreme opposites in unitary or bivariate dimensions. In this study, we applied transcranial direct current stimulation (tDCS to examine whether noninvasive brain stimulation modulates two types of aesthetic evaluation; evaluating beauty and ugliness. Participants rated the subjective beauty and ugliness of abstract paintings before and after the application of tDCS. Application of cathodal tDCS over the mPFC with anode electrode over the lPMC, which induced temporal inhibition of neural excitability of the mPFC, led to a decrease in beauty ratings but not ugliness ratings. There were no changes in ratings of both beauty and ugliness when applying anodal tDCS or sham stimulation over the mPFC. Results from our experiment indicate that the mPFC and the lPMC have a causal role in generating the subjective experience of beauty, with beauty and ugliness evaluations constituting two distinct dimensions.

  15. Copaiba Oil-Resin Treatment Is Neuroprotective and Reduces Neutrophil Recruitment and Microglia Activation after Motor Cortex Excitotoxic Injury

    OpenAIRE

    Adriano Guimarães-Santos; Diego Siqueira Santos; Ijair Rogério Santos; Rafael Rodrigues Lima; Antonio Pereira; Lucinewton Silva de Moura; Raul Nunes Carvalho; Osmar Lameira; Walace Gomes-Leal

    2012-01-01

    The oil-resin of Copaifera reticulata Ducke is used in the Brazilian folk medicine as an anti-inflammatory and healing agent. However, there are no investigations on the possible anti-inflammatory and neuroprotective roles of copaiba oil-resin (COR) after neural disorders. We have investigated the anti-inflammatory and neuroprotective effects of COR following an acute damage to the motor cortex of adult rats. Animals were injected with the neurotoxin N-Methyl-D-Aspartate (NMDA) (n = 10) and t...

  16. The human dorsal premotor cortex facilitates the excitability of ipsilateral primary motor cortex via a short latency cortico-cortical route

    DEFF Research Database (Denmark)

    Groppa, Sergiu; Schlaak, Boris H; Münchau, Alexander;

    2012-01-01

    subthreshold conditioning stimulus (CS) was given to PMd 2.0-5.2 ms after the TS at intensities of 50-, 70-, or 90% of TS. The CS to PMd facilitated the MEP evoked by TS over M1(HAND) at interstimulus intervals (ISI) of 2.4 or 2.8 ms. There was a second facilitatory peak at ISI of 4.4 ms. PMd-to-M1(HAND......In non-human primates, invasive tracing and electrostimulation studies have identified strong ipsilateral cortico-cortical connections between dorsal premotor- (PMd) and the primary motor cortex (M1(HAND) ). Here, we applied dual-site transcranial magnetic stimulation (dsTMS) to left PMd and M1......(HAND) through specifically designed minicoils to selectively probe ipsilateral PMd-to-M1(HAND) connectivity in humans. A suprathreshold test stimulus (TS) was applied to M1(HAND) producing a motor evoked potential (MEP) of about 0.5 mV in the relaxed right first dorsal interosseus muscle (FDI). A...

  17. The activity of the primary motor cortex ipsilateral to the exercising hand decreases during repetitive handgrip exercise

    International Nuclear Information System (INIS)

    The brain function controlling muscle force production is not yet fully understood. The purpose of this study was to examine bilateral primary motor cortex (M1) oxygenation during static-handgrip exercises performed with the right hand (60% maximal voluntary contraction; 10 s exercise/75 s rest; five sets). Twelve healthy, right-handed male subjects participated in this study. Near-infrared spectroscopy probes were positioned over the bilateral M1 to measure cortical oxygenation during handgrip exercises. The maximum values of the changes in concentrations of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) across the trials (i) did not change significantly during the contralateral M1 activation (p > 0.05), whereas (ii) in the case of the ipsilateral M1 activation a significant (p < 0.05) decrease in HbO2 and a significant (p < 0.01) decrease in Hb could be measured. The activation in ipsilateral M1 at the fifth trial was significantly decreased compared with that in the first trial (HbO2: p < 0.001; Hb: p < 0.001). The present results suggest that the ipsilateral M1 is recruited during the motor task in compensation for the contralateral M1 and the habituation to motor task might alter the efficiency for interaction of the ipsilateral M1 to the contralateral M1. The interhemispheric interaction might change due to habituation to motor task

  18. Changes in ipsilateral motor cortex activity during a unilateral isometric finger task are dependent on the muscle contraction force

    International Nuclear Information System (INIS)

    It is possible to examine bilateral primary motor cortex (M1) activation during a sustained motor task using near-infrared spectroscopy (NIRS), in which it is assumed that increased oxygenation reflects cortical activation. The purpose of this study was to examine bilateral M1 activation in response to graded levels of force production during a unilateral finger task. Ten healthy right-handed male subjects participated in this study. NIRS probes were placed over the cortex to measure M1 activity while the subjects performed the finger task. The subjects performed a 10 s finger task at 20%, 40%, and 60% of the maximal voluntary contraction (MVC). Symmetrical activation was found over both M1 areas at all force levels investigated. In the contralateral M1, there were significant differences in oxygenation between 20% and 60% MVC, as well as between 40% and 60% MVC. In the ipsilateral M1, there were significant differences among all force levels. These results indicate the ipsilateral M1 takes part in muscle force control. (paper)

  19. Correlation of near-infrared spectroscopy and transcranial magnetic stimulation of the motor cortex in overt reading and musical tasks.

    Science.gov (United States)

    Lo, Y L; Zhang, H H; Wang, C C; Chin, Z Y; Fook-Chong, S; Gabriel, C; Guan, C T

    2009-01-01

    In overt reading and singing tasks, actual vocalization of words in a rhythmic fashion is performed. During execution of these tasks, the role of underlying vascular processes in relation to cortical excitability changes in a spatial manner is uncertain. Our objective was to investigate cortical excitability changes during reading and singing with transcranial magnetic stimulation (TMS), as well as vascular changes with nearinfrared spectroscopy (NIRS). Findings with TMS and NIRS were correlated. TMS and NIRS recordings were performed in 5 normal subjects while they performed reading and singing tasks separately. TMS was applied over the left motor cortex at 9 positions 2.5 cm apart. NIRS recordings were made over these identical positions. Although both TMS and NIRS showed significant mean cortical excitability and hemodynamic changes from baseline during vocalization tasks, there was no significant spatial correlation of these changes evaluated with the 2 techniques over the left motor cortex. Our findings suggest that increased left-sided cortical excitability from overt vocalization tasks in the corresponding "hand area" were the result of "functional connectivity," rather than an underlying "vascular overflow mechanism" from the adjacent speech processing or face/mouth areas. Our findings also imply that functional neurophysiological and vascular methods may evaluate separate underlying processes, although subjects performed identical vocalization tasks. Future research combining similar methodologies should embrace this aspect and harness their separate capabilities. PMID:19246780

  20. How does transcranial DC stimulation of the primary motor cortex alter regional neuronal activity in the human brain?

    Science.gov (United States)

    Lang, Nicolas; Siebner, Hartwig R; Ward, Nick S; Lee, Lucy; Nitsche, Michael A; Paulus, Walter; Rothwell, John C; Lemon, Roger N; Frackowiak, Richard S

    2005-07-01

    Transcranial direct current stimulation (tDCS) of the primary motor hand area (M1) can produce lasting polarity-specific effects on corticospinal excitability and motor learning in humans. In 16 healthy volunteers, O positron emission tomography (PET) of regional cerebral blood flow (rCBF) at rest and during finger movements was used to map lasting changes in regional synaptic activity following 10 min of tDCS (+/-1 mA). Bipolar tDCS was given through electrodes placed over the left M1 and right frontopolar cortex. Eight subjects received anodal or cathodal tDCS of the left M1, respectively. When compared to sham tDCS, anodal and cathodal tDCS induced widespread increases and decreases in rCBF in cortical and subcortical areas. These changes in rCBF were of the same magnitude as task-related rCBF changes during finger movements and remained stable throughout the 50-min period of PET scanning. Relative increases in rCBF after real tDCS compared to sham tDCS were found in the left M1, right frontal pole, right primary sensorimotor cortex and posterior brain regions irrespective of polarity. With the exception of some posterior and ventral areas, anodal tDCS increased rCBF in many cortical and subcortical regions compared to cathodal tDCS. Only the left dorsal premotor cortex demonstrated an increase in movement related activity after cathodal tDCS, however, modest compared with the relatively strong movement-independent effects of tDCS. Otherwise, movement related activity was unaffected by tDCS. Our results indicate that tDCS is an effective means of provoking sustained and widespread changes in regional neuronal activity. The extensive spatial and temporal effects of tDCS need to be taken into account when tDCS is used to modify brain function. PMID:16045502

  1. Differential expression of secreted phosphoprotein 1 in the motor cortex among primate species and during postnatal development and functional recovery.

    Directory of Open Access Journals (Sweden)

    Tatsuya Yamamoto

    Full Text Available We previously reported that secreted phosphoprotein 1 (SPP1 mRNA is expressed in neurons whose axons form the corticospinal tract (CST of the rhesus macaque, but not in the corresponding neurons of the marmoset and rat. This suggests that SPP1 expression is involved in the functional or structural specialization of highly developed corticospinal systems in certain primate species. To further examine this hypothesis, we evaluated the expression of SPP1 mRNA in the motor cortex from three viewpoints: species differences, postnatal development, and functional/structural changes of the CST after a lesion of the lateral CST (l-CST at the mid-cervical level. The density of SPP1-positive neurons in layer V of the primary motor cortex (M1 was much greater in species with highly developed corticospinal systems (i.e., rhesus macaque, capuchin monkey, and humans than in those with less developed corticospinal systems (i.e., squirrel monkey, marmoset, and rat. SPP1-positive neurons in the macaque monkey M1 increased logarithmically in layer V during postnatal development, following a time course consistent with the increase in conduction velocity of the CST. After an l-CST lesion, SPP1-positive neurons increased in layer V of the ventral premotor cortex, in which compensatory changes in CST function/structure may occur, which positively correlated with the extent of finger dexterity recovery. These results further support the concept that the expression of SPP1 may reflect functional or structural specialization of highly developed corticospinal systems in certain primate species.

  2. Transcranial magnetic stimulation probes the excitability of the primary motor cortex: A framework to account for the facilitating effects of acute whole-body exercise on motor processes

    Directory of Open Access Journals (Sweden)

    Karen Davranche

    2015-03-01

    Full Text Available The effects of exercise on decision-making performance have been studied using a wide variety of cognitive tasks and exercise interventions. Although the current literature supports a beneficial influence of acute exercise on cognitive performance, the mechanisms underlying this phenomenon have not yet been elucidated. We review studies that used single-pulse transcranial magnetic stimulation (TMS to probe the excitability of motor structures during whole-body exercise and present a framework to account for the facilitating effects of acute exercise on motor processes. Recent results suggest that, even in the absence of fatigue, the increase in corticospinal excitability classically reported during submaximal and exhausting exercises may be accompanied by a reduction in intracortical inhibition. We propose that reduced intracortical inhibition elicits an adaptive central mechanism that counteracts the progressive reduction in muscle responsiveness caused by peripheral fatigue. Such a reduction would render the motor cortex more sensitive to upstream influences, thus causing increased corticospinal excitability. Furthermore, reduction of intracortical inhibition may account for the more efficient descending drive and for the improvement of reaction time performance during exercise. The adaptive modulation in intracortical inhibition could be implemented through a general increase in reticular activation that would further account for enhanced sensory sensitivity.

  3. Intra-operative recording of motor tract potentials at the cervico-medullary junction following scalp electrical and magnetic stimulation of the motor cortex.

    Science.gov (United States)

    Thompson, P D; Day, B L; Crockard, H A; Calder, I; Murray, N M; Rothwell, J C; Marsden, C D

    1991-07-01

    Activity in descending motor pathways after scalp electrical and magnetic brain stimulation of the motor cortex was recorded from the exposed cervico-medullary junction in six patients having trans-oral surgery of the upper cervical spine. Recordings during deep anaesthesia without muscle paralysis revealed an initial negative potential (D wave) at about 2 ms with electrical stimulation in five of the six patients. This was followed by a muscle potential which obscured any later waveforms. Magnetic stimulation produced clear potentials in only one patient. The earliest wave to magnetic stimulation during deep anaesthesia was 1-2 ms later than the earliest potential to electrical stimulation. Following lightening of the anaesthetic and the administration of muscle relaxants a series of later negative potentials (I waves) were more clearly seen to both electrical and magnetic stimulation. More I waves were recorded to magnetic stimulation during light anaesthesia than during deep anaesthesia. Increasing the intensity of electrical stimulation also produced an extra late I wave. At the highest intensity of magnetic stimulation the latency of the earliest potential was comparable to the D wave to electrical stimulation. The intervals between these various D and I waves corresponded to those previously described for the timing of single motor unit discharge after cortical stimulation. PMID:1654395

  4. Cerebellar influence on motor cortex plasticity: behavioral implications for Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    AshaKishore

    2014-05-01

    Full Text Available Normal motor behavior involves the creation of appropriate activity patterns across motor networks, enabling firing synchrony, synaptic integration and normal functioning of these net works. Strong topography-specific connections among the basal ganglia, cerebellum and their projections to overlapping areas in the motor cortices suggest that these networks could influence each other’s plastic responses and functions. The defective striatal signaling in Parkinson’s disease (PD could therefore lead to abnormal oscillatory activity and aberrant plasticity at multiple levels within the interlinked motor networks. Normal striatal dopaminergic signaling and cerebellar sensory processing functions influence the scaling and topographic specificity of M1 plasticity. Both these functions are abnormal in PD and appear to contribute to the abnormal M1 plasticity. Defective motor map plasticity and topographic specificity within M1 could lead to incorrect muscle synergies, which could manifest as abnormal or undesired movements, and as abnormal motor learning in PD. We propose that the loss of M1 plasticity in PD reflects a loss of co-ordination among the basal ganglia, cerebellar and cortical inputs which translates to an abnormal plasticity of motor maps within M1 and eventually to some of the motor signs of PD. The initial benefits of dopamine replacement therapy on M1 plasticity and motor signs are lost during the progressive course of disease. Levodopa-induced dyskinesias in patients with advanced PD is linked to a loss of M1 sensorimotor plasticity and the attenuation of dyskinesias by cerebellar inhibitory stimulation is associated with restoration of M1 plasticity. Complimentary interventions should target reestablishing physiological communication between the striatal and cerebellar circuits, and within striato-cerebellar loop. This may facilitate correct motor synergies and reduce abnormal movements in PD.

  5. Motor cortex-periaqueductal gray-spinal cord neuronal circuitry may involve in modulation of nociception: a virally mediated transsynaptic tracing study in spinally transected transgenic mouse model.

    Directory of Open Access Journals (Sweden)

    Da-Wei Ye

    Full Text Available Several studies have shown that motor cortex stimulation provided pain relief by motor cortex plasticity and activating descending inhibitory pain control systems. Recent evidence indicated that the melanocortin-4 receptor (MC4R in the periaqueductal gray played an important role in neuropathic pain. This study was designed to assess whether MC4R signaling existed in motor cortex-periaqueductal gray-spinal cord neuronal circuitry modulated the activity of sympathetic pathway by a virally mediated transsynaptic tracing study. Pseudorabies virus (PRV-614 was injected into the left gastrocnemius muscle in adult male MC4R-green fluorescent protein (GFP transgenic mice (n = 15. After a survival time of 4-6 days, the mice (n = 5 were randomly assigned to humanely sacrifice, and spinal cords and brains were removed and sectioned, and processed for PRV-614 visualization. Neurons involved in the efferent control of the left gastrocnemius muscle were identified following visualization of PRV-614 retrograde tracing. The neurochemical phenotype of MC4R-GFP-positive neurons was identified using fluorescence immunocytochemical labeling. PRV-614/MC4R-GFP dual labeled neurons were detected in spinal IML, periaqueductal gray and motor cortex. Our findings support the hypothesis that MC4R signaling in motor cortex-periaqueductal gray-spinal cord neural pathway may participate in the modulation of the melanocortin-sympathetic signaling and contribute to the descending modulation of nociceptive transmission, suggesting that MC4R signaling in motor cortex-periaqueductal gray-spinal cord neural pathway may modulate the activity of sympathetic outflow sensitive to nociceptive signals.

  6. Role of direct vs indirect pathways from the motor cortex to spinal motoneurons in the control of hand dexterity

    Directory of Open Access Journals (Sweden)

    Tadashi eIsa

    2013-11-01

    Full Text Available Evolutionally, development of the direct connection from the motor cortex to spinal motoneurons (corticomotoneuronal (CM pathway parallels the ability of hand dexterity. Damage to the corticofugal fibers in higher primates resulted in deficit of fractionated digit movements. Based on such observations, it was generally believed that the CM pathway plays a critical role in the control of hand dexterity. On the other hand, a number of phylogenetically older indirect pathways from the motor cortex to motoneurons still exist in primates. The indirect pathways are mediated by intercalated neurons such as segmental interneurons (sINs, propriospinal neurons (PNs reticulospinal neurons (RSNs or rubrospinal neurons (RuSNs. However, their contribution to hand dexterity remains elusive. Lesion of the brainstem pyramid sparing the transmission through the RuSNs and RSNs, resulted in permanent deficit of fractionated digit movements in macaque monkeys. On the other hand, in our recent study, after lesion of the dorsolateral funiculus (DLF at the C5 segment, which removed the CM pathway and the transmission through sINs and RuSNs but spared the processing through the PNs and RSNs, fractionated digit movements recovered within several weeks. These results suggest that the PNs can be involved in the recovery of fractionated digit movements, but the RSNs and RuSNs have less capacity in this regard. However, on closer inspection, it was found that the activation pattern of hand and arm muscles considerably changed after the C5 lesion, suggesting limitation of PNs for the compensation of hand dexterity. Altogether, it is suggested that PNs, RSNs RuSNs and the CM pathway (plus sINs make a different contribution to the hand dexterity and appearance of motor deficit of the hand dexterity caused by damage to the corticofugal fibers and potential of recovery varies depending on the rostrocaudal level of the lesion.

  7. Single to Two Cluster State Transition of Primary Motor Cortex 4-posterior (MI-4p Activities in Humans

    Directory of Open Access Journals (Sweden)

    Kazunori Nakada

    2015-11-01

    Full Text Available The human primary motor cortex has dual representation of the digits, namely, area 4 anterior (MI-4a and area 4 posterior (MI-4p. We have previously demonstrated that activation of these two functional subunits can be identified independently by functional magnetic resonance imaging (fMRI using independent component-cross correlation-sequential epoch (ICS analysis. Subsequent studies in patients with hemiparesis due to subcortical lesions and monoparesis due to peripheral nerve injury demonstrated that MI-4p represents the initiation area of activation, whereas MI-4a is the secondarily activated motor cortex requiring a “long-loop” feedback input from secondary motor systems, likely the cerebellum. A dynamic model of hand motion based on the limit cycle oscillator predicts that the specific pattern of entrainment of neural firing may occur by applying appropriate periodic stimuli. Under normal conditions, such entrainment introduces a single phase-cluster. Under pathological conditions where entrainment stimuli have insufficient strength, the phase cluster splits into two clusters. Observable physiological phenomena of this shift from single cluster to two clusters are: doubling of firing rate of output neurons; or decay in group firing density of the system due to dampening of odd harmonics components. While the former is not testable in humans, the latter can be tested by appropriately designed fMRI experiments, the quantitative index of which is believed to reflect group behavior of neurons functionally localized, e.g., firing density in the dynamic theory. Accordingly, we performed dynamic analysis of MI-4p activation in normal volunteers and paretic patients. The results clearly indicated that MI-4p exhibits a transition from a single to a two phase-cluster state which coincided with loss of MI-4a activation. The study demonstrated that motor dysfunction (hemiparesis in patients with a subcortical infarct is not simply due to afferent

  8. Functional magnetic resonance imaging of the primary motor cortex in humans: response to increased functional demands

    Indian Academy of Sciences (India)

    S Khushu; S S Kumaran; R P Tripathi; A Gupta; P C Jain; V Jain

    2001-06-01

    Functional magnetic resonance imaging (fMRI) studies have been performed on 20 right handed volunteers at 1.5 Tesla using echo planar imaging (EPI) protocol. Index finger tapping invoked localized activation in the primary motor area. Consistent and highly reproducible activation in the primary motor area was observed in six different sessions of a volunteer over a period of one month. Increased tapping rate resulted in increase in the blood oxygenation level dependent (BOLD) signal intensity as well as the volume/area of activation (pixels) in the contralateral primary motor area up to tapping rate of 120 taps/min (2 Hz), beyond which it saturates. Activation in supplementary motor area was also observed. The obtained results are correlated to increased functional demands.

  9. Changes in electrophysiological properties of cat hypoglossal motoneurons during carbachol-induced motor inhibition.

    Science.gov (United States)

    Fung, S J; Yamuy, J; Xi, M C; Engelhardt, J K; Morales, F R; Chase, M H

    2000-12-01

    The control of hypoglossal motoneurons during sleep is important from a basic science perspective as well as to understand the bases for pharyngeal occlusion which results in the obstructive sleep apnea syndrome. In the present work, we used intracellular recording techniques to determine changes in membrane properties in adult cats in which atonia was produced by the injection of carbachol into the pontine tegmentum (AS-carbachol). During AS-carbachol, 86% of the recorded hypoglossal motoneurons were found to be postsynaptically inhibited on the basis of analyses of their electrical properties; the electrical properties of the remaining 14% were similar to motoneurons recorded during control conditions. Those cells that exhibited changes in their electrical properties during AS-carbachol also displayed large-amplitude inhibitory synaptic potentials. Following sciatic nerve stimulation, hypoglossal motoneurons which responded with a depolarizing potential during control conditions exhibited a hyperpolarizing potential during AS-carbachol. Both spontaneous and evoked inhibitory potentials recorded during AS-carbachol were comparable to those that have been previously observed in trigeminal and spinal cord motoneurons under similar experimental conditions as well as during naturally occurring active sleep. Calculations based on modeling the changes that we found in input resistance and membrane time constant with a three-compartment neuron model suggest that shunts are present in all three compartments of the hypoglossal motoneuron model. Taken together, these data indicate that postsynaptic inhibitory drives are widely distributed on the soma-dendritic tree of hypoglossal motoneurons during AS-carbachol. These postsynaptic inhibitory actions are likely to be involved in the pathophysiology of obstructive sleep apnea. PMID:11102580

  10. Disruption of Functional Organization Within the Primary Motor Cortex in Children With Autism

    OpenAIRE

    Nebel, Mary Beth; Joel, Suresh E.; Muschelli, John; Barber, Anita D.; Caffo, Brian S.; Pekar, James J.; Mostofsky, Stewart H.

    2012-01-01

    Accumulating evidence suggests that motor impairments are prevalent in autism spectrum disorder (ASD), relate to the social and communicative deficits at the core of the diagnosis and may reflect abnormal connectivity within brain networks underlying motor control and learning. Parcellation of resting-state functional connectivity data using spectral clustering approaches has been shown to be an effective means of visualizing functional organization within the brain but has most commonly been...

  11. Neuropathic pain: transcranial electric motor cortex stimulation using high frequency random noise. Case report of a novel treatment

    Directory of Open Access Journals (Sweden)

    Alm PA

    2013-06-01

    Full Text Available Per A Alm, Karolina DreimanisDepartment of Neuroscience, Uppsala University, Uppsala, SwedenObjectives: Electric motor cortex stimulation has been reported to be effective for many cases of neuropathic pain, in the form of epidural stimulation or transcranial direct current stimulation (tDCS. A novel technique is transcranial random noise stimulation (tRNS, which increases the cortical excitability irrespective of the orientation of the current. The aim of this study was to investigate the effect of tRNS on neuropathic pain in a small number of subjects, and in a case study explore the effects of different stimulation parameters and the long-term stability of treatment effects.Methods: The study was divided into three phases: (1 a double-blind 100–600 Hz, varying from 0.5 to 10 minutes and from 50 to 1500 µA, at intervals ranging from daily to fortnightly.crossover study, with four subjects; (2 a double-blind extended case study with one responder; and (3 open continued treatment. The motor cortex stimulation consisted of alternating current random noise (100–600 Hz, varying from 0.5 to 10 minutes and from 50 to 1500 μA, at intervals ranging from daily to fortnightly.Results: One out of four participants showed a strong positive effect (also compared with direct-current-sham, P = 0.006. Unexpectedly, this effect was shown to occur also for very weak (100 µA, P = 0.048 and brief (0.5 minutes, P = 0.028 stimulation. The effect was largest during the first month, but remained at a highly motivating level for the patient after 6 months.Discussion: The study suggests that tRNS may be an effective treatment for some cases of neuropathic pain. An important result was the indication that even low levels of stimulation may have substantial effects.Keywords: neuropathic pain, central pain, transcranial direct current stimulation, motor cortex stimulation, random noise stimulation

  12. Blood oxygenation-level dependent functional MRI in evaluating the selective activation of motor cortexes associated with recovery of motor function in hemiplegic patients with ischemic stroke

    Institute of Scientific and Technical Information of China (English)

    Yuechun Li; Xiaoyan Liu; Guorong Liu; Ying He; Baojun Wang; Furu Liang; Li Wang; Hui Zhang; Jingfen Zhang; Ruiming Li

    2006-01-01

    an interval of 30 s. Te AVANTO 1.5T MRI machine (Siemens Company, Germany) was used for scanning, the 30 s before fMRI BOLD scanning was the adaptation phase for the patients, and the finger movements were alternated for 6-10 times till the end of the scanning.MAIN OUTCOME MEASURES: Differences after rehabilitation evaluated by the activations of different sensorimotor cortex in the hemiplegic patients with acute stroke. RESULTS: ① In passive and active movements of the affected hand, 5 cases of Brunnstrom grade Ⅰ or Ⅱ were manifested by the activation of unilateral sensorimotor cortex (SMC) of the hemiplegic side, and they were Brunnstrom grade Ⅱ after 3-week rehabilitation, and 1 case with activations of bilateral SMC recovered to Brunnstrom grade Ⅲ. ② Among the patients of Brunnstrom grade Ⅲ or Ⅳ, 5 cases were unilaterally activated, and had no changes after 3-week rehabilitation; Whereas of the 9 cases of bilateral activations, 3 recovered to grade Ⅵ and 6 recovered to grade Ⅴ after 3-week rehabilitation. ③ In the passive and active movements of the affected hand, all the cases of Brunnstrom grades Ⅴ and Ⅵ were manifested by the activations of bilateral SMC. After 3-week rehabilitation, 2 of the 4 cases of grade Ⅴ recovered to grade Ⅵ, and the other 2 recovered to normal; Whereas 5 of the 6 cases of grade Ⅵ recovered to normal, and the other 1 was still grade Ⅵ. CONCLUSION: BOLD fMRI showed that the outcomes of short-term rehabilitation in the patients with bilateral activations were obvious, whereas the outcomes were bad in the patients whose ipsilateral cortexes were activated. The activated signal in ipsilateral or bilateral SMC and the activation of supplementary motor area in active movements were greater than those in the passive ones.

  13. Mirror therapy in lower limb amputees. A look beyond primary motor cortex reorganization

    International Nuclear Information System (INIS)

    Phantom pain in upper limb amputees is associated with the extent of reorganization in the primary sensorimotor cortex. Mirror visual feedback therapy has been shown to improve phantom pain. We investigated the extent of cortical reorganization in lower limb amputees and changes in neural activity induced by mirror therapy. Eight lower limb amputees underwent 12 sessions of MVFT and functional magnetic resonance imaging (fMRI) of the brain before the first and after the last MVFT session. FMRI sessions consisted of two runs in which subjects were instructed to perform repetitive movement of the healthy and phantom ankle. Before MVFT, the mean phantom pain intensity was 4.6 ± 3.1 on a visual analog scale and decreased to 1.8 ± 1.7 (p = 0.04). We did not observe a consistent pattern of cortical activation in primary sensorimotor areas during phantom limb movements. Following MVFT, increased activity was obtained in the right orbitofrontal cortex during phantom ankle movements. Comparison of cortical activity during movements of the phantom ankle and the intact ankle showed significantly higher activity in the left inferior frontal cortex (pars triangularis). These results question the known association between phantom pain and primary sensorimotor reorganization and propose reorganizational changes involving multiple cortical areas in lower limb amputees. Finally, reduction of phantom pain after mirror visual feedback therapy was associated with increased prefrontal cortical activity during phantom ankle movements. (orig.)

  14. Mirror therapy in lower limb amputees. A look beyond primary motor cortex reorganization

    Energy Technology Data Exchange (ETDEWEB)

    Seidel, S.; Essmeister, M.; Sycha, T.; Auff, E. [Vienna Medical Univ. (Austria). Dept. of Neurology; Kasprian, G.; Furtner, J.; Schoepf, V.; Prayer, D. [Vienna Medical Univ. (Austria). Dept. of Neuroradiology

    2011-11-15

    Phantom pain in upper limb amputees is associated with the extent of reorganization in the primary sensorimotor cortex. Mirror visual feedback therapy has been shown to improve phantom pain. We investigated the extent of cortical reorganization in lower limb amputees and changes in neural activity induced by mirror therapy. Eight lower limb amputees underwent 12 sessions of MVFT and functional magnetic resonance imaging (fMRI) of the brain before the first and after the last MVFT session. FMRI sessions consisted of two runs in which subjects were instructed to perform repetitive movement of the healthy and phantom ankle. Before MVFT, the mean phantom pain intensity was 4.6 {+-} 3.1 on a visual analog scale and decreased to 1.8 {+-} 1.7 (p = 0.04). We did not observe a consistent pattern of cortical activation in primary sensorimotor areas during phantom limb movements. Following MVFT, increased activity was obtained in the right orbitofrontal cortex during phantom ankle movements. Comparison of cortical activity during movements of the phantom ankle and the intact ankle showed significantly higher activity in the left inferior frontal cortex (pars triangularis). These results question the known association between phantom pain and primary sensorimotor reorganization and propose reorganizational changes involving multiple cortical areas in lower limb amputees. Finally, reduction of phantom pain after mirror visual feedback therapy was associated with increased prefrontal cortical activity during phantom ankle movements. (orig.)

  15. Blood oxygenation level dependent functional MRI study on the changes of motor cortex in patients with amyotrophic lateral sclerosis

    International Nuclear Information System (INIS)

    Objective: To study the changes of motor cortex in patients with amyotrophic lateral sclerosis (ALS) while executing sequential finger tapping movement by using blood oxygenation level dependent (BOLD) functional MRI. Methods: Fifteen patients with definite or probable ALS and 15 age and gender matched normal controls were enrolled in the BOLD study, and all the subjects were right-handed with no other diseases or any recent medication history. A 3.0 T MR scanner' was employed and gradient echo EPI (GRE-EPI)sequence was used to acquire the functional images. Subjects executed sequential finger tapping movement at a frequency of 1-2 Hz during a block design task. fMRI data were analyzed by using statistical parametric mapping (SPM) 2. Volume of activated brain areas was compared with the use of a Student's t-test. Results: Bilateral primary sensorimotor cortex (PSM), bilateral posterior aspect of premotor area (PA), bilateral supplementary motor area (SMA), contralateral inferior lateral premotor area (ILPA), bilateral parietal region (PAR), and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task. The activation areas in bilateral PSM and bilateral posterior aspect of PA ( right hand ipsilateral activation: ALS (924.5±141.1) mm3, control (829.9± 98.4) mm3, P=0.05; right hand contralateral activation: ALS (9143.8±702.8) mm3, control (8638.8±506.4) mm3 P3, control (902.5±3 184.2)mm, P3, control (5934.6±616.4) mm3, P3, control (4710.7±416.3) mm3, P3, control (3688.9±672.3) mm3, P3, control (254.3±84.4) mm3, P3, control (1689.0±719.6) mm3, P<0.05) were significantly larger in ALS patients than in normal controls. Extra activation areas including ipsilateral ILPA, contralateral cerebellum and bilateral posterior limb of internal capsule were only detected in ALS patients. Conclusions: Similar activation areas were seen in both groups while executing the same motor task, but the activated areas

  16. Effects of volitional contraction on intracortical inhibition and facilitation in the human motor cortex

    OpenAIRE

    E. Ortu; F. Deriu; Suppa, A.; Tolu, E.; Rothwell, J. C.

    2008-01-01

    Short-interval intracortical inhibition (SICI), intracortical facilitation (ICF) and short-interval intracortical facilitation (SICF) were assessed in the cortical motor area of the first dorsal interosseous muscle (FDI) of 16 healthy subjects. Paired-pulse TMS was delivered to the left hemisphere at the following interstimulus intervals (ISIs): 2 and 3 ms for SICI, 10 and 15 ms for ICF and 1-5 ms for SICF. Motor-evoked potentials were recorded from the resting and active right FDI. The effec...

  17. JNK1 Controls Dendritic Field Size in L2/3 and L5 of the Motor Cortex, Constrains Soma Size and Influences Fine Motor Coordination

    Directory of Open Access Journals (Sweden)

    Emilia eKomulainen

    2014-09-01

    Full Text Available Genetic anomalies on the JNK pathway confer susceptibility to autism spectrum disorders, schizophrenia and intellectual disability. The mechanism whereby a gain or loss of function in JNK signaling predisposes to these prevalent dendrite disorders, with associated motor dysfunction, remains unclear. Here we find that JNK1 regulates the dendritic field of L2/3 and L5 pyramidal neurons of the mouse motor cortex (M1, the main excitatory pathway controlling voluntary movement. In Jnk1-/- mice, basal dendrite branching of L5 pyramidal neurons is increased in M1, as is cell soma size, whereas in L2/3, dendritic arborization is decreased. We show that JNK1 phosphorylates rat HMW-MAP2 on T1619, T1622 and T1625 (Uniprot P15146 corresponding to mouse T1617, T1620, T1623, to create a binding motif, that is critical for MAP2 interaction with and stabilization of microtubules, and dendrite growth control. Targeted expression in M1 of GFP-HMW-MAP2 that is pseudo-phosphorylated on T1619, T1622 and T1625 increases dendrite complexity in L2/3 indicating that JNK1 phosphorylation of HMW-MAP2 regulates the dendritic field. Consistent with the morphological changes observed in L2/3 and L5, Jnk1-/- mice exhibit deficits in limb placement and motor coordination, while stride length is reduced in older animals. In summary, JNK1 phosphorylates HMW-MAP2 to increase its stabilization of microtubules while at the same time controlling dendritic fields in the main excitatory pathway of M1. Moreover, JNK1 contributes to normal functioning of fine motor coordination. We report for the first time, a quantitative sholl analysis of dendrite architecture, and of motor behavior in Jnk1-/- mice. Our results illustrate the molecular and behavioral consequences of interrupted JNK1 signaling and provide new ground for mechanistic understanding of those prevalent neuropyschiatric disorders where genetic disruption of the JNK pathway is central.

  18. Molecular classification of amyotrophic lateral sclerosis by unsupervised clustering of gene expression in motor cortex

    NARCIS (Netherlands)

    E. Aronica; F. Baas; A. Iyer; A.L.M.A. ten Asbroek; G. Morello; S. Cavallaro

    2015-01-01

    Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and ultimately fatal neurodegenerative disease, caused by the loss of motor neurons in the brain and spinal cord. Although 10% of ALS cases are familial (FALS), the majority are sporadic (SALS) and probably associated to a multifactorial e

  19. Effects of excitation of sensory pathways on the membrane potential of cat masseter motoneurons before and during cholinergically induced motor atonia.

    Science.gov (United States)

    Kohlmeier, K A; López-Rodríguez, F; Morales, F R; Chase, M H

    1998-09-01

    Electrical stimulation of the nucleus pontis oralis during wakefulness enhances somatic reflex activity; identical stimuli during the motor atonia of active (rapid eye movement) sleep induces reflex suppression. This phenomenon, which is called reticular response-reversal, is based upon the generation of excitatory postsynaptic potential activity in motoneurons during wakefulness and inhibitory postsynaptic potential activity during the motor atonia of active sleep. In the present study, instead of utilizing artificial electrical stimulation to directly excite brainstem structures, we sought to examine the effects on motoneurons of activation of sensory pathways by exogenously applied stimuli (auditory) and by stimulation of a peripheral (sciatic) nerve. Accordingly, we examined the synaptic response of masseter motoneurons prior to and during cholinergically induced motor atonia in a pharmacological model of active sleep-specific motor atonia, the alpha-chloralose-anesthetized cat, to two different types of afferent input, one of which has been previously demonstrated to elicit excitatory motor responses during wakefulness. Following the pontine injection of carbachol, auditory stimuli (95 dB clicks) elicited a hyperpolarizing potential in masseter motoneurons. Similar responses were obtained upon stimulation of the sciatic nerve. Responses of this nature were never seen prior to the injection of carbachol. Thus, stimulation of two different afferent pathways (auditory and somatosensory) that produce excitatory motor responses during wakefulness instead, during motor atonia, results in the inhibition of masseter motoneurons. The switching of the net result of the synaptic response from one of potential motor excitation to primarily inhibition in response to the activation of sensory pathways was comparable to the phenomenon of reticular response-reversal. This is the first report to examine the synaptic mechanisms whereby exogenously or peripherally applied

  20. Changes in the axonal conduction velocity of pyramidal tract neurons in the aged cat.

    Science.gov (United States)

    Xi, M C; Liu, R H; Engelhardt, J K; Morales, F R; Chase, M H

    1999-01-01

    The present study was undertaken to determine whether age-dependent changes in axonal conduction velocity occur in pyramidal tract neurons. A total of 260 and 254 pyramidal tract neurons were recorded extracellularly in the motor cortex of adult control and aged cats, respectively. These cells were activated antidromically by electrical stimulation of the medullary pyramidal tract. Fast- and slow-conducting neurons were identified according to their axonal conduction velocity in both control and aged cats. While 51% of pyramidal tract neurons recorded in the control cats were fast conducting (conduction velocity greater than 20 m/s), only 26% of pyramidal tract neurons in the aged cats were fast conducting. There was a 43% decrease in the median conduction velocity for the entire population of pyramidal tract neurons in aged cats when compared with that of pyramidal tract neurons in the control cats (P cats. However, the regression slope was significantly reduced in aged cats. This reduction was due to the appearance of a group of pyramidal tract neurons with relatively shorter spike durations but slower axonal conduction velocities in the aged cat. Sample intracellular data confirmed the above results. These observations form the basis for the following conclusions: (i) there is a decrease in median conduction velocity of pyramidal tract neurons in aged cats; (ii) the reduction in the axonal conduction velocity of pyramidal tract neurons in aged cats is due, in part, to fibers that previously belonged to the fast-conducting group and now conduct at slower velocity. PMID:10392844

  1. Alterations in primary motor cortex neurotransmission and gene expression in hemi-parkinsonian rats with drug-induced dyskinesia.

    Science.gov (United States)

    Lindenbach, D; Conti, M M; Ostock, C Y; Dupre, K B; Bishop, C

    2015-12-01

    Treatment of Parkinson's disease (PD) with dopamine replacement relieves symptoms of poverty of movement, but often causes drug-induced dyskinesias. Accumulating clinical and pre-clinical evidence suggests that the primary motor cortex (M1) is involved in the pathophysiology of PD and that modulating cortical activity may be a therapeutic target in PD and dyskinesia. However, surprisingly little is known about how M1 neurotransmitter tone or gene expression is altered in PD, dyskinesia or associated animal models. The present study utilized the rat unilateral 6-hydroxydopamine (6-OHDA) model of PD/dyskinesia to characterize structural and functional changes taking place in M1 monoamine innervation and gene expression. 6-OHDA caused dopamine pathology in M1, although the lesion was less severe than in the striatum. Rats with 6-OHDA lesions showed a PD motor impairment and developed dyskinesia when given L-DOPA or the D1 receptor agonist, SKF81297. M1 expression of two immediate-early genes (c-Fos and ARC) was strongly enhanced by either L-DOPA or SKF81297. At the same time, expression of genes specifically involved in glutamate and GABA signaling were either modestly affected or unchanged by lesion and/or treatment. We conclude that M1 neurotransmission and signal transduction in the rat 6-OHDA model of PD/dyskinesia mirror features of human PD, supporting the utility of the model to study M1 dysfunction in PD and the elucidation of novel pathophysiological mechanisms and therapeutic targets. PMID:26363150

  2. Hypoactivation of the primary sensorimotor cortex in de novo Parkinson's disease. A motor fMRI study under controlled conditions

    International Nuclear Information System (INIS)

    Nuclear medicine studies in Parkinson's disease (PD) indicate that nigrostriatal damage causes a widespread cortical hypoactivity assumed to be due to reduced excitatory thalamic outflow. However, so far, functional MRI (fMRI) studies have provided controversial data about this ''functional deafferentation'' phenomenon. To further clarify this issue, we assessed, with fMRI, de novo drug-naive PD patients using a relatively complex motor task under strictly controlled conditions. Nineteen de novo PD patients with right-predominant or bilateral symptoms and 13 age-matched healthy volunteers performed continuous writing of ''8'' figures with the right-dominant hand using a MR-compatible device that enables identification of incorrectly performed tasks and measures the size and the frequency of the ''8''s. The data were analyzed with FSL software and correlated with the clinical severity rated according to the Hoehn and Yahr (HY) staging system. Fifteen (89%) of 19 PD patients and 12 (92%) of 13 controls correctly executed the task. PD patients showed significant hypoactivation of the left primary sensorimotor cortex (SM1) and cerebellum and no hyperactive areas as compared to controls. However, activation in SM1 and supplementary motor area bilaterally, in left supramarginal, parietal inferior, parietal superior and frontal superior gyri as well as in right parietal superior and angular gyri paralleled increasing disease severity as assessed with the HY stage. In line with the ''deafferentation hypothesis'', fMRI demonstrates hypoactivation of the SM1 in the early clinical stage of PD. (orig.)

  3. The role of pulse shape in motor cortex transcranial magnetic stimulation using full-sine stimuli

    DEFF Research Database (Denmark)

    Delvendahl, Igor; Gattinger, Norbert; Berger, Thomas;

    2014-01-01

    A full-sine (biphasic) pulse waveform is most commonly used for repetitive transcranial magnetic stimulation (TMS), but little is known about how variations in duration or amplitude of distinct pulse segments influence the effectiveness of a single TMS pulse to elicit a corticomotor response. Using...... a novel TMS device, we systematically varied the configuration of full-sine pulses to assess the impact of configuration changes on resting motor threshold (RMT) as measure of stimulation effectiveness with single-pulse TMS of the non-dominant motor hand area (M1). In young healthy volunteers, we (i...... considerably higher RMT, whereas varying the amplitude of the half-segment inducing anterior-posterior current had a smaller effect. These findings provide direct experimental evidence that the pulse segment inducing a posterior-anterior directed current in M1 contributes most to corticospinal pathway...

  4. A comparison between uni- and bilateral tDCS effects on functional connectivity of the human motor cortex

    Directory of Open Access Journals (Sweden)

    Bernhard Sehm

    2013-05-01

    Full Text Available tDCS over the primary motor cortex (M1 has been shown to induce changes in motor performance and learning. Recent studies indicate that tDCS is capable of modulating widespread neural network properties within the brain. However the temporal evolution of online- and after- effects of tDCS on functional connectivity within and across the stimulated motor cortices (M1 still remain elusive. In the present study, two different tDCS setups were investigated: (i unilateral M1 tDCS (anode over right M1, cathode over the contralateral supraorbital region and (ii bilateral M1 tDCS (anode over right M1, cathode over left M1. In a randomized single-blinded crossover design, 12 healthy subjects underwent resting-state functional magnetic resonance imaging at rest (rs-fMRI before, during and after 20 min of either bi-, unilateral or sham M1 tDCS. Seed-based functional connectivity analysis (FC was used to investigate tDCS-induced changes across and within M1. We found that bilateral M1 tDCS induced (a a decrease in interhemispheric FC during stimulation and (b an increase in intracortical FC within right M1 after termination of the intervention. While unilateral M1 tDCS also resulted in similar effects during stimulation, no such changes could be observed after termination of tDCS. Our results provide evidence that depending on the electrode montage, tDCS acts upon a modulation of either intracortical and/or interhemispheric processing of M1.

  5. Sustained excitability elevations induced by transcranial DC motor cortex stimulation in humans.

    Science.gov (United States)

    Nitsche, M A; Paulus, W

    2001-11-27

    The authors show that in the human transcranial direct current stimulation is able to induce sustained cortical excitability elevations. As revealed by transcranial magnetic stimulation, motor cortical excitability increased approximately 150% above baseline for up to 90 minutes after the end of stimulation. The feasibility of inducing long-lasting excitability modulations in a noninvasive, painless, and reversible way makes this technique a potentially valuable tool in neuroplasticity modulation. PMID:11723286

  6. Effects of an Exhaustive Exercise on Motor Skill Learning and on the Excitability of Primary Motor Cortex and Supplementary Motor Area.

    Science.gov (United States)

    Coco, Marinella; Perciavalle, Vincenzo; Cavallari, Paolo; Perciavalle, Valentina

    2016-03-01

    We examined, on 28 healthy adult subjects, the possible correlations of an exhaustive exercise, and the consequent high blood lactate levels, on immediate (explicit) and delayed (implicit) motor execution of sequential finger movements (cognitive task). Moreover, we determined with transcranial magnetic stimulation whether changes in motor performance are associated with variations in excitability of primary motor area (M1) and supplementary motor area (SMA). We observed that, after an acute exhaustive exercise, the large increase of blood lactate is associated with a significant worsening of both explicit and implicit sequential visuomotor task paradigms, without gender differences. We also found that, at the end of the exhaustive exercise, there is a change of excitability in both M1 and SMA. In particular, the excitability of M1 was increased whereas that of SMA decreased and, also in this case, without gender differences. These results support the idea that an increase of blood lactate after an exhaustive exercise appears to have a protective effect at level of primary cortical areas (as M1), although at the expense of efficiency of adjacent cortical regions (as SMA). PMID:26986109

  7. Effect of melatonin on motor performance and brain cortex mitochondrial function during ethanol hangover.

    Science.gov (United States)

    Karadayian, A G; Bustamante, J; Czerniczyniec, A; Cutrera, R A; Lores-Arnaiz, S

    2014-06-01

    Increased reactive oxygen species generation and mitochondrial dysfunction occur during ethanol hangover. The aim of this work was to study the effect of melatonin pretreatment on motor performance and mitochondrial function during ethanol hangover. Male mice received melatonin solution or its vehicle in drinking water during 7 days and i.p. injection with EtOH (3.8 g/kg BW) or saline at the eighth day. Motor performance and mitochondrial function were evaluated at the onset of hangover (6h after injection). Melatonin improved motor coordination in ethanol hangover mice. Malate-glutamate-dependent oxygen uptake was decreased by ethanol hangover treatment and partially prevented by melatonin pretreatment. Melatonin alone induced a decrease of 30% in state 4 succinate-dependent respiratory rate. Also, the activity of the respiratory complexes was decreased in melatonin-pretreated ethanol hangover group. Melatonin pretreatment before the hangover prevented mitochondrial membrane potential collapse and induced a 79% decrement of hydrogen peroxide production as compared with ethanol hangover group. Ethanol hangover induced a 25% decrease in NO production. Melatonin alone and as a pretreatment before ethanol hangover significantly increased NO production by nNOS and iNOS as compared with control groups. No differences were observed in nNOS protein expression, while iNOS expression was increased in the melatonin group. Increased NO production by melatonin could be involved in the decrease of succinate-dependent oxygen consumption and the inhibition of complex IV observed in our study. Melatonin seems to act as an antioxidant agent in the ethanol hangover condition but also exhibited some dual effects related to NO metabolism. PMID:24713372

  8. Effects of volitional contraction on intracortical inhibition and facilitation in the human motor cortex.

    Science.gov (United States)

    Ortu, Enzo; Deriu, Franca; Suppa, Antonio; Tolu, Eusebio; Rothwell, John C

    2008-11-01

    Short-interval intracortical inhibition (SICI), intracortical facilitation (ICF) and short-interval intracortical facilitation (SICF) were assessed in the cortical motor area of the first dorsal interosseous muscle (FDI) of 16 healthy subjects. Paired-pulse TMS was delivered to the left hemisphere at the following interstimulus intervals (ISIs): 2 and 3 ms for SICI, 10 and 15 ms for ICF and 1-5 ms for SICF. Motor-evoked potentials were recorded from the resting and active right FDI. The effects exerted on SICI and ICF by four intensities (60-90% of active motor threshold, AMT) of the conditioning stimulus (S1) and by three levels of muscle contraction (10%, 25%, 50% of maximal voluntary contraction, MVC) were evaluated. The effects exerted on SICF were evaluated with two intensities (90% and 70% of AMT) of the test stimulus (S2) and with the same levels of muscle contraction. Results showed that: (i) during 10% MVC, maximum SICI was observed with S1 = 70% AMT; (ii) the amount of SICI obtained with S1 = 70% AMT was the same at rest as during 10% MVC, but decreased at higher contraction levels; (iii) ICF was observed only at rest with S1 = 90% AMT; (iv) SICF was facilitated at 10% and 25% MVC, but not at 50% MVC. We conclude that during muscle activation, intracortical excitability reflects a balance between activation of SICI and SICF systems. Part of the reduction in SICI during contraction is due to superimposed recruitment of SICF. Low intensity (70% AMT) conditioning stimuli can test SICI independently of effects on SICF at low contraction levels. PMID:18787036

  9. Oxygen consumption and blood flow coupling in human motor cortex during intense finger tapping

    DEFF Research Database (Denmark)

    Seyedi Vafaee, Manouchehr; Vang, Kim; Bergersen, Linda H;

    2012-01-01

    (glc). To test whether the mismatch reflects a specific role of aerobic glycolysis during functional brain activation, we determined CBF and CMRO(2) with positron emission tomography (PET) when 12 healthy volunteers executed finger-to-thumb apposition of the right hand. Movements began 1, 10, or 20¿minutes...... before administration of the radiotracers. In primary and supplementary motor cortices and cerebellum, CBF had increased at 1¿minute of exercise and remained elevated for the duration of the 20-minute session. In contrast, the CMRO(2) numerically had increased insignificantly in left M1 and supplementary...

  10. Comparison of LFP-based and spike-based spectro-temporal receptive fields and cross-correlation in cat primary auditory cortex.

    Directory of Open Access Journals (Sweden)

    Jos J Eggermont

    Full Text Available Multi-electrode array recordings of spike and local field potential (LFP activity were made from primary auditory cortex of 12 normal hearing, ketamine-anesthetized cats. We evaluated 259 spectro-temporal receptive fields (STRFs and 492 frequency-tuning curves (FTCs based on LFPs and spikes simultaneously recorded on the same electrode. We compared their characteristic frequency (CF gradients and their cross-correlation distances. The CF gradient for spike-based FTCs was about twice that for 2-40 Hz-filtered LFP-based FTCs, indicating greatly reduced frequency selectivity for LFPs. We also present comparisons for LFPs band-pass filtered between 4-8 Hz, 8-16 Hz and 16-40 Hz, with spike-based STRFs, on the basis of their marginal frequency distributions. We find on average a significantly larger correlation between the spike based marginal frequency distributions and those based on the 16-40 Hz filtered LFP, compared to those based on the 4-8 Hz, 8-16 Hz and 2-40 Hz filtered LFP. This suggests greater frequency specificity for the 16-40 Hz LFPs compared to those of lower frequency content. For spontaneous LFP and spike activity we evaluated 1373 pair correlations for pairs with >200 spikes in 900 s per electrode. Peak correlation-coefficient space constants were similar for the 2-40 Hz filtered LFP (5.5 mm and the 16-40 Hz LFP (7.4 mm, whereas for spike-pair correlations it was about half that, at 3.2 mm. Comparing spike-pairs with 2-40 Hz (and 16-40 Hz LFP-pair correlations showed that about 16% (9% of the variance in the spike-pair correlations could be explained from LFP-pair correlations recorded on the same electrodes within the same electrode array. This larger correlation distance combined with the reduced CF gradient and much broader frequency selectivity suggests that LFPs are not a substitute for spike activity in primary auditory cortex.

  11. Comparison of LFP-based and spike-based spectro-temporal receptive fields and cross-correlation in cat primary auditory cortex.

    Science.gov (United States)

    Eggermont, Jos J; Munguia, Raymundo; Pienkowski, Martin; Shaw, Greg

    2011-01-01

    Multi-electrode array recordings of spike and local field potential (LFP) activity were made from primary auditory cortex of 12 normal hearing, ketamine-anesthetized cats. We evaluated 259 spectro-temporal receptive fields (STRFs) and 492 frequency-tuning curves (FTCs) based on LFPs and spikes simultaneously recorded on the same electrode. We compared their characteristic frequency (CF) gradients and their cross-correlation distances. The CF gradient for spike-based FTCs was about twice that for 2-40 Hz-filtered LFP-based FTCs, indicating greatly reduced frequency selectivity for LFPs. We also present comparisons for LFPs band-pass filtered between 4-8 Hz, 8-16 Hz and 16-40 Hz, with spike-based STRFs, on the basis of their marginal frequency distributions. We find on average a significantly larger correlation between the spike based marginal frequency distributions and those based on the 16-40 Hz filtered LFP, compared to those based on the 4-8 Hz, 8-16 Hz and 2-40 Hz filtered LFP. This suggests greater frequency specificity for the 16-40 Hz LFPs compared to those of lower frequency content. For spontaneous LFP and spike activity we evaluated 1373 pair correlations for pairs with >200 spikes in 900 s per electrode. Peak correlation-coefficient space constants were similar for the 2-40 Hz filtered LFP (5.5 mm) and the 16-40 Hz LFP (7.4 mm), whereas for spike-pair correlations it was about half that, at 3.2 mm. Comparing spike-pairs with 2-40 Hz (and 16-40 Hz) LFP-pair correlations showed that about 16% (9%) of the variance in the spike-pair correlations could be explained from LFP-pair correlations recorded on the same electrodes within the same electrode array. This larger correlation distance combined with the reduced CF gradient and much broader frequency selectivity suggests that LFPs are not a substitute for spike activity in primary auditory cortex. PMID:21625385

  12. Neural control of the sphincter of Oddi. A physiological role of 5-hydroxytryptamine in the regulation of basal sphincter of Oddi motor activity in the cat.

    OpenAIRE

    Behar, J; Biancani, P

    1983-01-01

    The effect of 5-hydroxytryptamine (5-HT) on the sphincter of Oddi (SO) was studied in the cat. The SO had two motor responses to 5-HT: the most common was an initial contraction followed by a more prolonged relaxation, and the other was an exclusive relaxation. Tetrodotoxin did not impair the magnitude of the net contraction induced by 5-HT, but it completely blocked the relaxation. Methysergide partially inhibited the SO contraction in response to submaximal doses of 5-HT (5-20 micrograms/kg...

  13. Direct classification of all American English phonemes using signals from functional speech motor cortex

    Science.gov (United States)

    Mugler, Emily M.; Patton, James L.; Flint, Robert D.; Wright, Zachary A.; Schuele, Stephan U.; Rosenow, Joshua; Shih, Jerry J.; Krusienski, Dean J.; Slutzky, Marc W.

    2014-06-01

    Objective. Although brain-computer interfaces (BCIs) can be used in several different ways to restore communication, communicative BCI has not approached the rate or efficiency of natural human speech. Electrocorticography (ECoG) has precise spatiotemporal resolution that enables recording of brain activity distributed over a wide area of cortex, such as during speech production. In this study, we sought to decode elements of speech production using ECoG. Approach. We investigated words that contain the entire set of phonemes in the general American accent using ECoG with four subjects. Using a linear classifier, we evaluated the degree to which individual phonemes within each word could be correctly identified from cortical signal. Main results. We classified phonemes with up to 36% accuracy when classifying all phonemes and up to 63% accuracy for a single phoneme. Further, misclassified phonemes follow articulation organization described in phonology literature, aiding classification of whole words. Precise temporal alignment to phoneme onset was crucial for classification success. Significance. We identified specific spatiotemporal features that aid classification, which could guide future applications. Word identification was equivalent to information transfer rates as high as 3.0 bits s-1 (33.6 words min-1), supporting pursuit of speech articulation for BCI control.

  14. Rhythmic Continuous-Time Coding in the Songbird Analog of Vocal Motor Cortex.

    Science.gov (United States)

    Lynch, Galen F; Okubo, Tatsuo S; Hanuschkin, Alexander; Hahnloser, Richard H R; Fee, Michale S

    2016-05-18

    Songbirds learn and produce complex sequences of vocal gestures. Adult birdsong requires premotor nucleus HVC, in which projection neurons (PNs) burst sparsely at stereotyped times in the song. It has been hypothesized that PN bursts, as a population, form a continuous sequence, while a different model of HVC function proposes that both HVC PN and interneuron activity is tightly organized around motor gestures. Using a large dataset of PNs and interneurons recorded in singing birds, we test several predictions of these models. We find that PN bursts in adult birds are continuously and nearly uniformly distributed throughout song. However, we also find that PN and interneuron firing rates exhibit significant 10-Hz rhythmicity locked to song syllables, peaking prior to syllable onsets and suppressed prior to offsets-a pattern that predominates PN and interneuron activity in HVC during early stages of vocal learning. PMID:27196977

  15. [Changes in the parameters of locomotion following partial extirpation of the motor cortex in white rats].

    Science.gov (United States)

    Lenkov, D N; Vereshchak, N I

    1989-01-01

    Quantitative locomotion changes have been studied in the norm and in different periods after local ablation of motor projection of hind paw in the right hemisphere of 5-16 weeks white rats. The length and width of step gradually increase with the age, and coefficients of gait asymmetry reflecting individual characteristics, are relatively stable in intact animals. Local decortication is accompanied by significant shifts of all locomotion parameters clearly expressed in the first days after ablation. The most sensitive characteristic of gait anomaly is the standard deviation of half-step. In 5 weeks after ablation a lag is observed of operated rats behind the control ones in all parameters. Load application contributes to revealing of locomotion parameters shifts from the norm in later periods after decortication. In 9 and 11 weeks after surgery, the signs of supercompensation are observed in a number of parameters. PMID:2735116

  16. Impairments of motor-cortex responses to unilateral and bilateral direct current stimulation in schizophrenia

    Directory of Open Access Journals (Sweden)

    AlkomietHasan

    2013-10-01

    Full Text Available Transcranial direct current stimulation (tDCS is a non-invasive stimulation technique that can be applied to modulate cortical activity through induction of cortical plasticity. Since various neuropsychiatric disorders are characterised by fluctuations in cortical activity levels (e.g. schizophrenia, tDCS is increasingly investigated as a treatment tool. Several studies have shown that the induction of cortical plasticity following classical, unilateral tDCS is reduced or impaired in the stimulated and non-stimulated primary motor cortices (M1 of schizophrenia patients. Moreover, an alternative, bilateral tDCS setup has recently been shown to modulate cortical plasticity in both hemispheres in healthy subjects, highlighting another potential treatment approach. Here we present the first study comparing the efficacy of unilateral tDCS (cathode left M1, anode right supraorbital with simultaneous bilateral tDCS (cathode left M1, anode right M1 in schizophrenia patients. tDCS-induced cortical plasticity was monitored by investigating motor-evoked potentials induced by single-pulse transcranial magnetic stimulation applied to both hemispheres. Healthy subjects showed a reduction of left M1 excitability following unilateral tDCS on the stimulated left hemisphere and an increase in right M1 excitability following bilateral tDCS. In schizophrenia, no plasticity was induced following both stimulation paradigms. The pattern of these results indicates a complex interplay between plasticity and connectivity that is impaired in schizophrenia patients. Further studies are needed to clarify the biological underpinnings and clinical impact of these findings.

  17. The role of pulse shape in motor cortex transcranial magnetic stimulation using full-sine stimuli.

    Directory of Open Access Journals (Sweden)

    Igor Delvendahl

    Full Text Available A full-sine (biphasic pulse waveform is most commonly used for repetitive transcranial magnetic stimulation (TMS, but little is known about how variations in duration or amplitude of distinct pulse segments influence the effectiveness of a single TMS pulse to elicit a corticomotor response. Using a novel TMS device, we systematically varied the configuration of full-sine pulses to assess the impact of configuration changes on resting motor threshold (RMT as measure of stimulation effectiveness with single-pulse TMS of the non-dominant motor hand area (M1. In young healthy volunteers, we (i compared monophasic, half-sine, and full-sine pulses, (ii applied two-segment pulses consisting of two identical half-sines, and (iii manipulated amplitude, duration, and current direction of the first or second full-sine pulse half-segments. RMT was significantly higher using half-sine or monophasic pulses compared with full-sine. Pulses combining two half-sines of identical polarity and duration were also characterized by higher RMT than full-sine stimuli resulting. For full-sine stimuli, decreasing the amplitude of the half-segment inducing posterior-anterior oriented current in M1 resulted in considerably higher RMT, whereas varying the amplitude of the half-segment inducing anterior-posterior current had a smaller effect. These findings provide direct experimental evidence that the pulse segment inducing a posterior-anterior directed current in M1 contributes most to corticospinal pathway excitation. Preferential excitation of neuronal target cells in the posterior-anterior segment or targeting of different neuronal structures by the two half-segments can explain this result. Thus, our findings help understanding the mechanisms of neural stimulation by full-sine TMS.

  18. Three-dimensional visualization of functional brain tissue and functional magnetic resonance imaging-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex

    International Nuclear Information System (INIS)

    Objective: To assess the value of three -dimensional visualization of functional brain tissue and the functional magnetic resonance imaging (fMRI)-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex. Method: Sixty patients with tumor located in the central sulcus were enrolled. Thirty patients were randomly assigned to function group and 30 to control group. Patients in function group underwent fMRI to localize the functional brain tissues. Then the function information was transferred to the neurosurgical navigator. The patients in control group underwent surgery with navigation without function information. The therapeutic effect, excision rate. improvement of motor function, and survival quality during follow-up were analyzed. Result: All patients in function group were accomplished visualization of functional brain tissues and fMRI-integrated neuronavigation. The locations of tumors, central sulcus and motor cortex were marked during the operation. The fMRI -integrated information played a great role in both pre- and post-operation. Pre-operation: designing the location of the skin flap and window bone, determining the relationship between the tumor and motor cortex, and designing the pathway for the resection. Post- operation: real-time navigation of relationship between the tumor and motor cortex, assisting to localize the motor cortex using interoperation ultra-sound for correcting the displacement by the CSF outflow and collapsing tumor. The patients in the function group had better results than the patients in the control group in therapeutic effect (u=2.646, P=0.008), excision rate (χ=7.200, P<0.01), improvement of motor function (u=2.231, P=0.026), and survival quality (KPS uc= 2.664, P=0.008; Zubrod -ECOG -WHO uc=2.135, P=0.033). Conclusions: Using preoperative three -dimensional visualization of cerebral function tissue and the fMRI-integrated neuronavigation technology, combining intraoperative accurate positioning

  19. Responses of single corticospinal neurons to intracortical stimulation of primary motor and premotor cortex in the anesthetized macaque monkey.

    Science.gov (United States)

    Maier, Marc A; Kirkwood, Peter A; Brochier, Thomas; Lemon, Roger N

    2013-06-01

    The responses of individual primate corticospinal neurons to localized electrical stimulation of primary motor (M1) and of ventral premotor cortex (area F5) are poorly documented. To rectify this and to study interactions between responses from these areas, we recorded corticospinal axons, identified by pyramidal tract stimulation, in the cervical spinal cord of three chloralose-anesthetized macaque monkeys. Single stimuli (≤400 μA) were delivered to the hand area of M1 or F5 through intracortical microwire arrays. Only 14/112 (13%) axons showed responses to M1 stimuli that indicated direct intracortical activation of corticospinal neurons (D-responses); no D-responses were seen from F5. In contrast, 62 axons (55%) exhibited consistent later responses to M1 stimulation, corresponding to indirect activation (I-responses), showing that single-pulse intracortical stimulation of motor areas can result in trans-synaptic activation of a high proportion of the corticospinal output. A combined latency histogram of all axon responses was nonperiodic, clearly different from the periodic surface-recorded corticospinal volleys. This was readily explained by correcting for conduction velocities of individual axons. D-responding axons, taken as originating in neurons close to the M1 stimulating electrodes, showed more I-responses from M1 than those without a D-response, and 8/10 of these axons also responded to F5 stimulation. Altogether, 33% of tested axons responded to F5 stimulation, most of which also showed I-responses from M1. These excitatory effects are in keeping with facilitation of hand muscles evoked from F5 being relayed via M1. This was further demonstrated by facilitation of test responses from M1 by conditioning F5 stimuli. PMID:23536718

  20. The primary motor cortex is associated with learning the absolute, but not relative, timing dimension of a task: A tDCS study.

    Science.gov (United States)

    Apolinário-Souza, Tércio; Romano-Silva, Marco Aurélio; de Miranda, Débora Marques; Malloy-Diniz, Leandro Fernandes; Benda, Rodolfo Novellino; Ugrinowitsch, Herbert; Lage, Guilherme Menezes

    2016-06-01

    The functional role of the primary motor cortex (M1) in the production of movement parameters, such as length, direction and force, is well known; however, whether M1 is associated with the parametric adjustments in the absolute timing dimension of the task remains unknown. Previous studies have not applied tasks and analyses that could separate the absolute (variant) and relative (invariant) dimensions. We applied transcranial direct current stimulation (tDCS) to M1 before motor practice to facilitate motor learning. A sequential key-pressing task was practiced with two goals: learning the relative timing dimension and learning the absolute timing dimension. All effects of the stimulation of M1 were observed only in the absolute dimension of the task. Mainly, the stimulation was associated with better performance in the transfer test in the absolute dimension. Taken together, our results indicate that M1 is an important area for learning the absolute timing dimension of a motor sequence. PMID:27018089

  1. Implementación de un driver para motores paso a paso mediante microcontroladores ARM-CORTEX M3 con sistema operativo en tiempo real

    OpenAIRE

    López García, Jesús

    2012-01-01

    Este proyecto contiene el diseño e implementación de un sistema de control electrónico para un motor paso a paso bipolar. Dicho sistema está basado en un microcontrolador de 32 bits de la familia ARM-Cortex-M3® que se comunica por USB con el PC para recibir órdenes precisas por parte del usuario. El microcontrolador ejecuta los algoritmos de aceleración/deceleración necesarios para suavizar los movimientos del motor. El sistema operativo en tiempo real, uC/OS-II, permite al microcontrolador c...

  2. Copaiba oil-resin treatment is neuroprotective and reduces neutrophil recruitment and microglia activation after motor cortex excitotoxic injury.

    Science.gov (United States)

    Guimarães-Santos, Adriano; Santos, Diego Siqueira; Santos, Ijair Rogério; Lima, Rafael Rodrigues; Pereira, Antonio; de Moura, Lucinewton Silva; Carvalho, Raul Nunes; Lameira, Osmar; Gomes-Leal, Walace

    2012-01-01

    The oil-resin of Copaifera reticulata Ducke is used in the Brazilian folk medicine as an anti-inflammatory and healing agent. However, there are no investigations on the possible anti-inflammatory and neuroprotective roles of copaiba oil-resin (COR) after neural disorders. We have investigated the anti-inflammatory and neuroprotective effects of COR following an acute damage to the motor cortex of adult rats. Animals were injected with the neurotoxin N-Methyl-D-Aspartate (NMDA) (n = 10) and treated with a single dose of COR (400 mg/kg, i.p.) soon after surgery (Group 1) or with two daily doses (200 mg/kg, i.p.) during 3 days (Group 2) alter injury. Control animals were treated with vehicle only. COR treatment induced tissue preservation and decreased the recruitment of neutrophils and microglial activation in the injury site compared to vehicle animals. The results suggest that COR treatment induces neuroprotection by modulating inflammatory response following an acute damage to the central nervous system. PMID:22461843

  3. Primary sensory and motor cortex function in response to acute muscle pain: A systematic review and meta-analysis.

    Science.gov (United States)

    Burns, E; Chipchase, L S; Schabrun, S M

    2016-09-01

    Acute muscle pain has both motor and sensory consequences, yet the effect of muscle pain on the primary sensory (S1) and motor (M1) cortices has yet to be systematically evaluated. Here we aimed to determine the strength of the evidence for (1) altered activation of S1/M1 during and after pain, (2) the temporal profile of any change in activation and (3) the relationship between S1/M1 activity and the symptoms of pain. In September 2015, five electronic databases were systematically searched for neuroimaging and electrophysiological studies investigating the effect of acute experimental muscle pain on S1/M1 in healthy volunteers. Demographic data, methodological characteristics and primary outcomes for each study were extracted for critical appraisal. Meta-analyses were performed where appropriate. Twenty-five studies satisfied the inclusion criteria. There was consistent evidence from fMRI for increased S1 activation in the contralateral hemisphere during pain, but insufficient evidence to determine the effect at M1. Meta-analyses of TMS and EEG data revealed moderate to strong evidence of reduced S1 and corticomotor excitability during and following the resolution of muscle pain. A comprehensive understanding of the temporal profile of altered activity in S1/M1, and the relationship to symptoms of pain, is hampered by differences in methodological design, pain modality and pain severity between studies. Overall, the findings of this review indicate reduced S1 and corticomotor activity during and after resolution of acute muscle pain, mechanisms that could plausibly underpin altered sensorimotor function in pain. WHAT DOES THIS REVIEW ADD?: We provide the first systematic evaluation of the primary sensory (S1) and motor (M1) cortex response to acute experimental muscle pain in healthy volunteers. We present evidence from a range of methodologies to provide a comprehensive understanding of the effect of pain on S1/M1. Through meta-analyses we evaluate the strength

  4. Influence of position and stimulation parameters on intracortical inhibition and facilitation in human tongue motor cortex

    DEFF Research Database (Denmark)

    Kothari, Mohit; Svensson, Peter; Nielsen, Jørgen Feldbæk;

    recorded from contralateral tongue muscles. In study 1, single pulse and three ppTMS ISIs: 2, 10, 15 ms were applied 8 times each in three blocks (TS: 120%, 140% and 160% of resting motor threshold (rMT); CS: 80% of rMT) in two different body positions (recline and supine) randomly. In study 2, single......Paired-pulse transcranial magnetic stimulation (ppTMS) can be used to assess short-interval intracortical inhibitory (SICI) and facilitatory (ICF) networks. The aim of the study was to examine the influence of body positions (recline and supine), inter-stimulus intervals (ISI) between the test...... pulse and four ppTMS ISIs: 2, 2.5, 3, 3.5 ms were applied 8 times each in randomized order in two blocks (CS: 70% and 80% of rMT; TS: 120% of rMT). There was a significant effect of body position (P=0.049), TS intensities (P<0.001) and ISIs (P<0.001) and interaction between intensity and ISIs (P=0...

  5. Providing and optimizing functional MR (Magnetic Resonance) of motor cortex of human brain by MRI ( Magnetic Resonance Imaging) facilities of Imam Khomeinie Hospital

    International Nuclear Information System (INIS)

    Display of human brain cortical activity is accomplished using various techniques, by them different spatial and temporal resolution may be obtained. F MRI technique with proper spatial and temporal resolution due to its noninvasivity is one of the promising techniques for detection of brain activities. This can be used as an important tool by neurologists, since a great development has been achieved for display different brain function. This thesis report the results of simulation effects of thumb motor cortex of normal volunteer by using conventional standard 1.5 T imager and optimized gradient echo techniques. Activating sensory and motor stimulations can be led to, respective cortical area of that stimulation by which oxygenated blood flow is increased in that area (Bold contrast). By designing of a T 2* sensitized gradient echo protocol, thumb's sensory and motor cortex activation is evaluated. A protocol known as FASTin picker system with the following specifications was used for F MRI: Band Width:24 Hz/Pixel, Tr=101 m Sec , T E=49 m Sec , Flip Angle= 10 deg., N E X=1 ,Slice thickness=5-7 mm F O V=250 mm ,Matrix=128*128 and total scan time= 14 Sec. Stimulation of the motor cortex was performed by periodic movement of dominant thumb in up-down and right-left direction within a Lshape trajectory of plastic sheet with a frequency about 2 Hz. Then, acquired images in rest and stimulation period were evaluated by S P M 97, S P M 99 b software. During the stimulation, an observable increased signal (%2-%5)in respective sensory-motor cortex was obtained after correcting for partial volume effects, optimizing S/N,and incorporating small vowels. The 2 D F A S T functional image obtained by this method, showed an anatomical association of the increased signal with gray matter of sensory-motor cortex(in T 1 weighted image). The resultant data showed the feasibility of functional magnetic resonance imaging using optimized gradient echo sequences on a standard 1.5 T

  6. Non-invasive Transcranial Magnetic Stimulation (TMS of the Motor Cortex for Neuropathic Pain—At the Tipping Point?

    Directory of Open Access Journals (Sweden)

    Roi Treister

    2013-10-01

    Full Text Available The term “neuropathic pain” (NP refers to chronic pain caused by illnesses or injuries that damage peripheral or central pain-sensing neural pathways to cause them to fire inappropriately and signal pain without cause. Neuropathic pain is common, complicating diabetes, shingles, HIV, and cancer. Medications are often ineffective or cause various adverse effects, so better approaches are needed. Half a century ago, electrical stimulation of specific brain regions (neuromodulation was demonstrated to relieve refractory NP without distant effects, but the need for surgical electrode implantation limited use of deep brain stimulation. Next, electrodes applied to the dura outside the brain’s surface to stimulate the motor cortex were shown to relieve NP less invasively. Now, electromagnetic induction permits cortical neurons to be stimulated entirely non-invasively using transcranial magnetic stimulation (TMS. Repeated sessions of many TMS pulses (rTMS can trigger neuronal plasticity to produce long-lasting therapeutic benefit. Repeated TMS already has US and European regulatory approval for treating refractory depression, and multiple small studies report efficacy for neuropathic pain. Recent improvements include “frameless stereotactic” neuronavigation systems, in which patients’ head MRIs allow TMS to be applied to precise underlying cortical targets, minimizing variability between sessions and patients, which may enhance efficacy. Transcranial magnetic stimulation appears poised for the larger trials necessary for regulatory approval of a NP indication. Since few clinicians are familiar with TMS, we review its theoretical basis and historical development, summarize the neuropathic pain trial results, and identify issues to resolve before large-scale clinical trials.

  7. Effects of Chronic Sleep Restriction during Early Adolescence on the Adult Pattern of Connectivity of Mouse Secondary Motor Cortex123

    Science.gov (United States)

    Billeh, Yazan N.; Bernard, Amy; de Vivo, Luisa; Honjoh, Sakiko; Mihalas, Stefan; Ng, Lydia; Koch, Christof

    2016-01-01

    Abstract Cortical circuits mature in stages, from early synaptogenesis and synaptic pruning to late synaptic refinement, resulting in the adult anatomical connection matrix. Because the mature matrix is largely fixed, genetic or environmental factors interfering with its establishment can have irreversible effects. Sleep disruption is rarely considered among those factors, and previous studies have focused on very young animals and the acute effects of sleep deprivation on neuronal morphology and cortical plasticity. Adolescence is a sensitive time for brain remodeling, yet whether chronic sleep restriction (CSR) during adolescence has long-term effects on brain connectivity remains unclear. We used viral-mediated axonal labeling and serial two-photon tomography to measure brain-wide projections from secondary motor cortex (MOs), a high-order area with diffuse projections. For each MOs target, we calculated the projection fraction, a combined measure of passing fibers and axonal terminals normalized for the size of each target. We found no homogeneous differences in MOs projection fraction between mice subjected to 5 days of CSR during early adolescence (P25–P30, ≥50% decrease in daily sleep, n=14) and siblings that slept undisturbed (n=14). Machine learning algorithms, however, classified animals at significantly above chance levels, indicating that differences between the two groups exist, but are subtle and heterogeneous. Thus, sleep disruption in early adolescence may affect adult brain connectivity. However, because our method relies on a global measure of projection density and was not previously used to measure connectivity changes due to behavioral manipulations, definitive conclusions on the long-term structural effects of early CSR require additional experiments. PMID:27351022

  8. Effects of Chronic Sleep Restriction during Early Adolescence on the Adult Pattern of Connectivity of Mouse Secondary Motor Cortex.

    Science.gov (United States)

    Billeh, Yazan N; Rodriguez, Alexander V; Bellesi, Michele; Bernard, Amy; de Vivo, Luisa; Funk, Chadd M; Harris, Julie; Honjoh, Sakiko; Mihalas, Stefan; Ng, Lydia; Koch, Christof; Cirelli, Chiara; Tononi, Giulio

    2016-01-01

    Cortical circuits mature in stages, from early synaptogenesis and synaptic pruning to late synaptic refinement, resulting in the adult anatomical connection matrix. Because the mature matrix is largely fixed, genetic or environmental factors interfering with its establishment can have irreversible effects. Sleep disruption is rarely considered among those factors, and previous studies have focused on very young animals and the acute effects of sleep deprivation on neuronal morphology and cortical plasticity. Adolescence is a sensitive time for brain remodeling, yet whether chronic sleep restriction (CSR) during adolescence has long-term effects on brain connectivity remains unclear. We used viral-mediated axonal labeling and serial two-photon tomography to measure brain-wide projections from secondary motor cortex (MOs), a high-order area with diffuse projections. For each MOs target, we calculated the projection fraction, a combined measure of passing fibers and axonal terminals normalized for the size of each target. We found no homogeneous differences in MOs projection fraction between mice subjected to 5 days of CSR during early adolescence (P25-P30, ≥ 50% decrease in daily sleep, n=14) and siblings that slept undisturbed (n=14). Machine learning algorithms, however, classified animals at significantly above chance levels, indicating that differences between the two groups exist, but are subtle and heterogeneous. Thus, sleep disruption in early adolescence may affect adult brain connectivity. However, because our method relies on a global measure of projection density and was not previously used to measure connectivity changes due to behavioral manipulations, definitive conclusions on the long-term structural effects of early CSR require additional experiments. PMID:27351022

  9. Association between the fMRI manifestations of activated brain areas and muscle strength in patients with space-occupying lesions in motor cortex

    Institute of Scientific and Technical Information of China (English)

    Wenbin Zheng; Xiaoke Chen; Guorui Liu; Renhua Wu

    2006-01-01

    BACKGROUND: Functional magnetic resonance imaging (fMRI) studies have disclosed the changes of the motor function in the motor cortex of ipsilateral and contralateral hemispheres of tumor, which have special significance for making the surgical planning and most greatly minimizing the postoperative functional damages.OBJECTIVE: To analyze the association between the manifestation characteristics of hand functional area and motor dysfunction using fMRI in patients with space-occupying lesions of tumor in motor cortex.DESIGN: A case-controlled observation.SETTING: Department of Radiology, Second Affiliated Hospital, Shantou University Medical College.PARTICIPANTS: Twenty-three patients (13 males and 10 females) with space-occupying lesions of central sulcus area, aged 21-53 years with a mean age of (47±1) years were selected from the Second Affiliated Hospital of Shantou University Medical College. All the patients were diagnosed by MR scanning as space-occupying lesions of motor area, and pathologically confirmed that the lesions involved central sulcus and central Iobule; Lesions occurred in left and right hemispheres in 13 and 10 cases respectively. The tumcr types were astrocytoma (n =8), metastatic tumours (n =7), meningiomas (n =5) and oligodendroglioma (n =3). The muscle strength was normal in 11 cases (grade 5) and obviously decreased in 12 cases (grade 2-3 in 3 cases and grade 4 in 9 cases); muscle strengths of both upper and lower limbs were decreased in 7 cases, and only that of upper limbs was decreased in 5 cases. Informed consents were obtained from all the subjects. Meanwhile, 9 healthy physical examinees (5 males and 4 females) of 20-56 years old with an average of (34±1) years were taken as controls. All the patients and healthy subjects were right-handed.METHODS: All the enrolled subjects were examined with MR scanning and functional imaging. Twenty cases whose clinical symptoms were mild in the patient group and 9 healthy volunteers adopted

  10. Dimensions of individual alpha and gamma motor fibres in the ventral funiculus of the cat spinal cord.

    OpenAIRE

    Fabricius, C.; Berthold, C H; Rydmark, M

    1994-01-01

    Using light and electron microscopy, axon diameter, myelin sheath thickness (measured as number of myelin lamellae) and internodal length of alpha and gamma motor axons of the L7 ventral root and spinal cord segment were investigated in serial cross-sections. The CNS internodes of the alpha motor fibres had, on average, an axon diameter of 8.6 microns, 105 myelin lamellae and a length of about 560 microns. The CNS internodes of the gamma motor fibres had, on average, an axon diameter of 3.4 m...

  11. Estudio de los datos del catálogo en motores de inducción trifásicos

    OpenAIRE

    Carreño Peña, Silvia

    2009-01-01

    En este estudio queremos conseguir parametrizar los componentes del circuito equivalente por fase de un motor trifásico de inducción, de manera que podamos saber como sera el comportamiento de dicho motor sin tener que realizar ningún tipo de ensayo en el laboratorio. Hemos estudiado diferentes motores donde sus potencias y números de polos son diferentes, en un principio hemos estudiado tres tipos de potencias y 4 variaciones en el número de par de polos. Una vez obtenido las gráficas de tod...

  12. Hemispheric asymmetry of frequency-dependent suppression in the ipsilateral primary motor cortex during finger movement: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Hayashi, Masamichi J; Saito, Daisuke N; Aramaki, Yu; Asai, Tatsuya; Fujibayashi, Yasuhisa; Sadato, Norihiro

    2008-12-01

    Electrophysiological studies have suggested that the activity of the primary motor cortex (M1) during ipsilateral hand movement reflects both the ipsilateral innervation and the transcallosal inhibitory control from its counterpart in the opposite hemisphere, and that their asymmetry might cause hand dominancy. To examine the asymmetry of the involvement of the ipsilateral motor cortex during a unimanual motor task under frequency stress, we conducted block-design functional magnetic resonance imaging with 22 normal right-handed subjects. The task involved visually cued unimanual opponent finger movement at various rates. The contralateral M1 showed symmetric frequency-dependent activation. The ipsilateral M1 showed task-related deactivation at low frequencies without laterality. As the frequency of the left-hand movement increased, the left M1 showed a gradual decrease in the deactivation. This data suggests a frequency-dependent increased involvement of the left M1 in ipsilateral hand control. By contrast, the right M1 showed more prominent deactivation as the frequency of the right-hand movement increased. This suggests that there is an increased transcallosal inhibition from the left M1 to the right M1, which overwhelms the right M1 activation during ipsilateral hand movement. These results demonstrate the dominance of the left M1 in both ipsilateral innervation and transcallosal inhibition in right-handed individuals. PMID:18413350

  13. Layer 5 Pyramidal Neurons’ Dendritic Remodeling and Increased Microglial Density in Primary Motor Cortex in a Murine Model of Facial Paralysis

    Directory of Open Access Journals (Sweden)

    Diana Urrego

    2015-01-01

    Full Text Available This work was aimed at characterizing structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with microglial density induced by facial nerve lesion using a murine facial paralysis model. Adult transgenic mice, expressing green fluorescent protein in microglia and yellow fluorescent protein in projecting neurons, were submitted to either unilateral section of the facial nerve or sham surgery. Injured animals were sacrificed either 1 or 3weeks after surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1. It was found that facial nerve lesion induced long-lasting changes in the dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Dendritic arborization of the pyramidal cells underwent overall shrinkage. Apical dendrites suffered transient shortening while basal dendrites displayed sustained shortening. Moreover, dendrites suffered transient spine pruning. Significantly higher microglial cell density was found surrounding vM1 layer 5 pyramidal neurons after facial nerve lesion with morphological bias towards the activated phenotype. These results suggest that facial nerve lesions elicit active dendrite remodeling due to pyramidal neuron and microglia interaction, which could be the pathophysiological underpinning of some neuropathic motor sequelae in humans.

  14. A network for sensory-motor integration: what happens in the auditory cortex during piano playing without acoustic feedback?

    Science.gov (United States)

    Baumann, Simon; Koeneke, Susan; Meyer, Martin; Lutz, Kai; Jäncke, Lutz

    2005-12-01

    Playing a musical instrument requires efficient auditory as well as motor processing. We provide evidence for the existence of a neuronal network of secondary and higher-order areas belonging to the auditory and motor modality that is important in the integration of auditory and motor domains. PMID:16597763

  15. Systemic blockade of dopamine D2-like receptors increases high-voltage spindles in the globus pallidus and motor cortex of freely moving rats.

    Directory of Open Access Journals (Sweden)

    Chen Yang

    Full Text Available High-voltage spindles (HVSs have been reported to appear spontaneously and widely in the cortical-basal ganglia networks of rats. Our previous study showed that dopamine depletion can significantly increase the power and coherence of HVSs in the globus pallidus (GP and motor cortex of freely moving rats. However, it is unclear whether dopamine regulates HVS activity by acting on dopamine D₁-like receptors or D₂-like receptors. We employed local-field potential and electrocorticogram methods to simultaneously record the oscillatory activities in the GP and primary motor cortex (M1 in freely moving rats following systemic administration of dopamine receptor antagonists or saline. The results showed that the dopamine D₂-like receptor antagonists, raclopride and haloperidol, significantly increased the number and duration of HVSs, and the relative power associated with HVS activity in the GP and M1 cortex. Coherence values for HVS activity between the GP and M1 cortex area were also significantly increased by dopamine D₂-like receptor antagonists. On the contrary, the selective dopamine D₁-like receptor antagonist, SCH23390, had no significant effect on the number, duration, or relative power of HVSs, or HVS-related coherence between M1 and GP. In conclusion, dopamine D₂-like receptors, but not D₁-like receptors, were involved in HVS regulation. This supports the important role of dopamine D₂-like receptors in the regulation of HVSs. An siRNA knock-down experiment on the striatum confirmed our conclusion.

  16. Changes in synapse quantity and growth associated protein 43 expression in the motor cortex of focal cerebral ischemic rats following catalpol treatment

    Institute of Scientific and Technical Information of China (English)

    Dong Wan; Huifeng Zhu; Yong Luo; Peng Xie

    2011-01-01

    The present study investigated the effects of catalpol, the main constituent of the Chinese herb Rehmannia root, on neurons following brain ischemia. A rat model of focal permanent brain ischemia was established using electrocoagulation. The rats were intraperitoneally injected with catalpol, at a dose of 5 mg/kg, daily for 1 week. Results showed that the number of neuronal synapses in the motor cortex and growth associated protein 43 expression were increased following catalpol treatment, indicating that catalpol might contribute to neuroplasticity and ameliorate functional neurological deficits induced by cerebral ischemia.

  17. Bihemispheric Motor Cortex Transcranial Direct Current Stimulation Improves Force Steadiness in Post-Stroke Hemiparetic Patients: A Randomized Crossover Controlled Trial.

    Science.gov (United States)

    Montenegro, Rafael A; Midgley, Adrian; Massaferri, Renato; Bernardes, Wendell; Okano, Alexandre H; Farinatti, Paulo

    2016-01-01

    Post-stroke patients usually exhibit reduced peak muscular torque (PT) and/or force steadiness during submaximal exercise. Brain stimulation techniques have been proposed to improve neural plasticity and help to restore motor performance in post-stroke patients. The present study compared the effects of bihemispheric motor cortex transcranial direct current stimulation (tDCS) on PT and force steadiness during maximal and submaximal resistance exercise performed by post-stroke patients vs. healthy controls. A double-blind randomized crossover controlled trial (identification number: TCTR20151112001; URL: http://www.clinicaltrials.in.th/) was conducted involving nine healthy and 10 post-stroke hemiparetic individuals who received either tDCS (2 mA) or sham stimulus upon the motor cortex for 20 min. PT and force steadiness (reflected by the coefficient of variation (CV) of muscular torque) were assessed during unilateral knee extension and flexion at maximal and submaximal workloads (1 set of 3 repetitions at 100% PT and 2 sets of 10 repetitions at 50% PT, respectively). No significant change in PT was observed in post-stroke and healthy subjects. Force steadiness during knee extension (~25-35%, P < 0.001) and flexion (~22-33%, P < 0.001) improved after tDCS compared to the sham condition in post-stroke patients, but improved only during knee extension (~13-27%, P < 0.001) in healthy controls. These results suggest that tDCS may improve force steadiness, but not PT in post-stroke hemiparetic patients, which might be relevant in the context of motor rehabilitation programs. PMID:27601988

  18. Predominance of Movement Speed Over Direction in Neuronal Population Signals of Motor Cortex: Intracranial EEG Data and A Simple Explanatory Model.

    Science.gov (United States)

    Hammer, Jiří; Pistohl, Tobias; Fischer, Jörg; Kršek, Pavel; Tomášek, Martin; Marusič, Petr; Schulze-Bonhage, Andreas; Aertsen, Ad; Ball, Tonio

    2016-06-01

    How neuronal activity of motor cortex is related to movement is a central topic in motor neuroscience. Motor-cortical single neurons are more closely related to hand movement velocity than speed, that is, the magnitude of the (directional) velocity vector. Recently, there is also increasing interest in the representation of movement parameters in neuronal population activity, such as reflected in the intracranial EEG (iEEG). We show that in iEEG, contrasting to what has been previously found on the single neuron level, speed predominates over velocity. The predominant speed representation was present in nearly all iEEG signal features, up to the 600-1000 Hz range. Using a model of motor-cortical signals arising from neuronal populations with realistic single neuron tuning properties, we show how this reversal can be understood as a consequence of increasing population size. Our findings demonstrate that the information profile in large population signals may systematically differ from the single neuron level, a principle that may be helpful in the interpretation of neuronal population signals in general, including, for example, EEG and functional magnetic resonance imaging. Taking advantage of the robust speed population signal may help in developing brain-machine interfaces exploiting population signals. PMID:26984895

  19. Providing and optimizing functional MR (Magnetic Resonance) of motor cortex of human brain by MRI ( Magnetic Resonance Imaging) facilities of Imam Khomeinie Hospital

    CERN Document Server

    Khosravie, H R

    2000-01-01

    During the stimulation, an observable increased signal (%2-%5)in respective sensory-motor cortex was obtained after correcting for partial volume effects, optimizing S/N,and incorporating small vowels. The 2 D F A S T functional image obtained by this method, showed an anatomical association of the increased signal with gray matter of sensory-motor cortex(in T 1 weighted image). The resultant data showed the feasibility of functional magnetic resonance imaging using optimized gradient echo sequences on a standard 1.5 T imager. Display of human brain cortical activity is accomplished using various techniques, by them different spatial and temporal resolution may be obtained. F MRI technique with proper spatial and temporal resolution due to its noninvasivity is one of the promising techniques for detection of brain activities. This can be used as an important tool by neurologists, since a great development has been achieved for display different brain function. This thesis report the results of simulation effe...

  20. A Concept for Extending the Applicability of Constraint-Induced Movement Therapy through Motor Cortex Activity Feedback Using a Neural Prosthesis

    Directory of Open Access Journals (Sweden)

    Fiachra Matthews

    2007-09-01

    Full Text Available This paper describes a concept for the extension of constraint-induced movement therapy (CIMT through the use of feedback of primary motor cortex activity. CIMT requires residual movement to act as a source of feedback to the patient, thus preventing its application to those with no perceptible movement. It is proposed in this paper that it is possible to provide feedback of the motor cortex effort to the patient by measurement with near infrared spectroscopy (NIRS. Significant changes in such effort may be used to drive rehabilitative robotic actuators, for example. This may provide a possible avenue for extending CIMT to patients hitherto excluded as a result of severity of condition. In support of such a paradigm, this paper details the current status of CIMT and related attempts to extend rehabilitation therapy through the application of technology. An introduction to the relevant haemodynamics is given including a description of the basic technology behind a suitable NIRS system. An illustration of the proposed therapy is described using a simple NIRS system driving a robotic arm during simple upper-limb unilateral isometric contraction exercises with healthy subjects.

  1. Induction of active (REM) sleep and motor inhibition by hypocretin in the nucleus pontis oralis of the cat.

    Science.gov (United States)

    Xi, Ming-Chu; Fung, Simon J; Yamuy, Jack; Morales, Francisco R; Chase, Michael H

    2002-06-01

    Hypocretin (orexin)-containing neurons in the hypothalamus, which have been implicated in the pathology of narcolepsy, project to nuclei in the brain stem reticular formation that are involved in the control of the behavioral states of sleep and wakefulness. Among these nuclei is the nucleus pontis oralis (NPO). Consequently, the present study was undertaken to determine if the hypocretinergic system provides regulatory input to neurons in the NPO with respect to the generation of the states of sleep and wakefulness. Accordingly, polygraphic recordings and behavioral observations were obtained before and after hypocretin-1 and -2 were microinjected into the NPO in chronic, unanesthetized cats. Microinjections of either hypocretin-1 or -2 elicited, with a short latency, a state of active [rapid eye movement (REM)] sleep that appeared identical to naturally occurring active sleep. The percentage of time spent in active sleep was significantly increased. Dissociated states, which are characterized by the presence of muscle atonia without one or more of the electrophysiological correlates of active sleep, also arose following the injection. The effect of juxtacellular application of hypocretin-1 on the electrical activity of intracellularly recorded NPO neurons was then examined in the anesthetized cat. In this preparation, the application of hypocretin-1 resulted in the depolarization of NPO neurons, an increase in the frequency of their discharge and an increase in their excitability. These latter data represent the first description of the in vivo action of hypocretin on intracellularly recorded neuronal activity and provide evidence that the active sleep-inducing effects of hypocretin are due to a direct excitatory action on NPO neurons. Therefore we suggest that hypocretinergic processes in the NPO may play a role in the generation of active sleep, particularly muscle atonia and therefore are likely to be involved in the pathology of narcolepsy. PMID:12037191

  2. Variation in left posterior parietal-motor cortex interhemispheric facilitation following right parietal continuous theta-burst stimulation in healthy adults.

    Science.gov (United States)

    Killington, Christopher; Barr, Christopher; Loetscher, Tobias; Bradnam, Lynley V

    2016-08-25

    Spatial neglect is modeled on an imbalance of interhemispheric inhibition (IHI); however evidence is emerging that it may not explain neglect in all cases. The aim of this study was to investigate the IHI imbalance model of visual neglect in healthy adults, using paired pulse transcranial magnetic stimulation to probe excitability of projections from posterior parietal cortex (PPC) to contralateral primary motor cortex (M1) bilaterally. Motor-evoked potentials (MEPs) were recorded from the first dorsal interossei and facilitation was determined as ratio of conditioned to non-conditioned MEP amplitude. A laterality index reflecting the balance of excitability between the two hemispheres was calculated. A temporal order judgment task (TOJ) assessed visual attention. Continuous theta-burst stimulation was used to transiently suppress right parietal cortex activity and the effect on laterality and judgment task measured, along with associations between baseline and post stimulation measures. Stimulation had conflicting results on laterality, with most participants demonstrating an effect in the negative direction with no decrement in the TOJ task. Correlation analysis suggests a strong association between laterality direction and degree of facilitation of left PPC-to right M1 following stimulation (r=.902), with larger MEP facilitation at baseline demonstrating greater reduction (r=-.908). Findings indicate there was relative balance between the cortices at baseline but right PPC suppression did not evoke left PPC facilitation in most participants, contrary to the IHI imbalance model. Left M1 facilitation prior to stimulation may predict an individual's response to continuous theta-burst stimulation of right PPC. PMID:27267243

  3. Grey matter volume and resting-state functional connectivity of the motor cortex-cerebellum network reflect the individual variation in masticatory performance in the healthy elderly people

    Directory of Open Access Journals (Sweden)

    Chia-Shu eLin

    2016-01-01

    Full Text Available Neuroimaging studies have consistently identified brain activation in the motor area and the cerebellum during chewing. In this study, we further investigated the structural and functional brain signature associated with masticatory performance, which is a widely used index for evaluating overall masticatory function in the elderly. Twenty-five healthy elderly participants underwent oral examinations, masticatory performance tests, and behavioral assessments, including the Cognitive Abilities Screening Instrument and the short-form Geriatric Depression Scale. Masticatory performance was assessed with the validated colorimetric method, using color-changeable chewing gum. T1-weighted structural magnetic resonance imaging (MRI and resting-state function MRI were performed. We analyzed alterations in grey matter volume (GMV using voxel-based morphometry and resting-state functional connectivity (rsFC between brain regions using the seed-based method. The structural and functional MRI analyses revealed the following findings: (1 the GMV change in the premotor cortex was positively correlated with masticatory performance. (2 The rsFC between the cerebellum and the premotor cortex was positively correlated with masticatory performance. (3 The GMV changes in the dorsolateral prefrontal cortex (DLPFC, as well as the rsFC between the cerebellum and the DLPFC, was positively correlated with masticatory performance. The findings showed that in the premotor cortex, a reduction of GMV and rsFC would reflect declined masticatory performance. The positive correlation between DLPFC connectivity and masticatory performance implies that masticatory ability is associated with cognitive function in the elderly. Our findings highlighted the role of the central nervous system in masticatory performance and increased our understanding of the structural and functional brain signature underlying individual variations in masticatory performance in the elderly.

  4. Cortical and thalamic connectivity of the auditory anterior ectosylvian cortex of early-deaf cats: Implications for neural mechanisms of crossmodal plasticity.

    Science.gov (United States)

    Meredith, M Alex; Clemo, H Ruth; Corley, Sarah B; Chabot, Nicole; Lomber, Stephen G

    2016-03-01

    Early hearing loss leads to crossmodal plasticity in regions of the cerebrum that are dominated by acoustical processing in hearing subjects. Until recently, little has been known of the connectional basis of this phenomenon. One region whose crossmodal properties are well-established is the auditory field of the anterior ectosylvian sulcus (FAES) in the cat, where neurons are normally responsive to acoustic stimulation and its deactivation leads to the behavioral loss of accurate orienting toward auditory stimuli. However, in early-deaf cats, visual responsiveness predominates in the FAES and its deactivation blocks accurate orienting behavior toward visual stimuli. For such crossmodal reorganization to occur, it has been presumed that novel inputs or increased projections from non-auditory cortical areas must be generated, or that existing non-auditory connections were 'unmasked.' These possibilities were tested using tracer injections into the FAES of adult cats deafened early in life (and hearing controls), followed by light microscopy to localize retrogradely labeled neurons. Surprisingly, the distribution of cortical and thalamic afferents to the FAES was very similar among early-deaf and hearing animals. No new visual projection sources were identified and visual cortical connections to the FAES were comparable in projection proportions. These results support an alternate theory for the connectional basis for cross-modal plasticity that involves enhanced local branching of existing projection terminals that originate in non-auditory as well as auditory cortices. PMID:26724756

  5. Increase in Short-Interval Intracortical Facilitation of the Motor Cortex after Low-Frequency Repetitive Magnetic Stimulation of the Unaffected Hemisphere in the Subacute Phase after Stroke

    Science.gov (United States)

    Mello, Eduardo Arruda; Cohen, Leonardo G.; Monteiro dos Anjos, Sarah; Conti, Juliana; Andrade, Karina Nocelo F.; Tovar Moll, Fernanda; Marins, Theo; Fernandes, Corina A.; Rodrigues, Waldyr; Conforto, Adriana Bastos

    2015-01-01

    Low-frequency repetitive transcranial magnetic stimulation of the unaffected hemisphere (UH-LF-rTMS) in patients with stroke can decrease interhemispheric inhibition from the unaffected to the affected hemisphere and improve hand dexterity and strength of the paretic hand. The objective of this proof-of-principle study was to explore, for the first time, effects of UH-LF-rTMS as add-on therapy to motor rehabilitation on short-term intracortical inhibition (SICI) and intracortical facilitation (ICF) of the motor cortex of the unaffected hemisphere (M1UH) in patients with ischemic stroke. Eighteen patients were randomized to receive, immediately before rehabilitation treatment, either active or sham UH-LF-rTMS, during two weeks. Resting motor threshold (rMT), SICI, and ICF were measured in M1UH before the first session and after the last session of treatment. There was a significant increase in ICF in the active group compared to the sham group after treatment, and there was no significant differences in changes in rMT or SICI. ICF is a measure of intracortical synaptic excitability, with a relative contribution of spinal mechanisms. ICF is typically upregulated by glutamatergic agonists and downregulated by gabaergic antagonists. The observed increase in ICF in the active group, in this hypothesis-generating study, may be related to M1UH reorganization induced by UH-LF-rTMS. PMID:26060584

  6. No effects of 20 Hz-rTMS of the primary motor cortex in vegetative state: A randomised, sham-controlled study.

    Science.gov (United States)

    Cincotta, Massimo; Giovannelli, Fabio; Chiaramonti, Roberta; Bianco, Giovanni; Godone, Marco; Battista, Donato; Cardinali, Consuelo; Borgheresi, Alessandra; Sighinolfi, Antonella; D'Avanzo, Anna Maria; Breschi, Marco; Dine, Ylli; Lino, Mario; Zaccara, Gaetano; Viggiano, Maria Pia; Rossi, Simone

    2015-10-01

    We assessed the effects of a non-invasive neuromodulatory intervention with repetitive transcranial magnetic stimulation (rTMS) of the motor cortex in patients with vegetative state (VS) by a randomised, sham-controlled study with a cross-over design. Eleven patients classified as being in VS (9 post-anoxic, 2 post-traumatic, time elapsed from the injury 9-85 months) were included in the study. Real or sham 20 Hz rTMS were applied to the left primary motor cortex (M1) for 5 consecutive days. Primary outcome measures were changes in the JFK Coma Recovery Scale-Revised (CRS-R) scale total score and Clinical Global Impression Improvement (CGI-I) scale. Additional measures were EEG changes and impression of the patients' relatives using the CGI-I scale. Evaluations were blindly performed at baseline, after the first day of treatment, immediately after the end of the 5-days treatment, 1 week and 1 month later. Slight changes observed in the CRS-R and CGI-I scores did not significantly differ between real or sham stimulation conditions. EEG was not significantly changed on average, although spots of brain reactivity were occasionally found underneath the stimulation point. Findings did not provide evidence of therapeutic effect of 20 Hz rTMS of the M1 in chronic VS, at least with conventional coils and current safety parameters. Therefore, they might be useful to better allocate human and financial resources in future trials. PMID:26301875

  7. Effects of left primary motor and dorsolateral prefrontal cortex transcranial direct current stimulation on laser-evoked potentials in migraine patients and normal subjects.

    Science.gov (United States)

    Vecchio, Eleonora; Ricci, Katia; Montemurno, Anna; Delussi, Marianna; Invitto, Sara; de Tommaso, Marina

    2016-07-28

    Migraine is characterized by an altered cortical excitability. Because transcranial direct current stimulation (tDCS) can change brain activity noninvasively, it is possible to hypothesize its efficacy in modulating pain in migraine. In this study, we compared the effects of tDCS of the left primary motor cortex (M1) and left dorsolateral prefrontal cortex (DLPFC) both on subjective pain and on evoked responses induced by laser stimulation (LEPs). Thirty-two patients and sixteen controls were randomized to receive sham stimulation and real tDCS with the anode centered over M1 or DLPFC. Laser Evoked potentials were recorded in basal, sham and tDCS conditions. We did not find significant acute changes in LEPs parameters and pain perception among subjects who received tDCS of both M1 and DLPFC. After DLPFC tDCS, we observed a significant increase of N2-P2 component habituation in migraine patients while M1 stimulation reduced it. These findings may suggest a modulation of abnormal pain processing induced by DLPFC and M1 anodal tDCS and outline the need for future investigations exploring the possible neuronal plasticity changes supporting the clinical effect on migraine. PMID:27208831

  8. Brain-derived neurotrophic factor--a major player in stimulation-induced homeostatic metaplasticity of human motor cortex?

    DEFF Research Database (Denmark)

    Mastroeni, Claudia; Bergmann, Til Ole; Rizzo, Vincenzo;

    2013-01-01

    Repetitive transcranial magnetic stimulation (rTMS) of the human motor hand area (M1HAND) can induce lasting changes in corticospinal excitability as indexed by a change in amplitude of the motor-evoked potential. The plasticity-inducing effects of rTMS in M1HAND show substantial inter-individual......Repetitive transcranial magnetic stimulation (rTMS) of the human motor hand area (M1HAND) can induce lasting changes in corticospinal excitability as indexed by a change in amplitude of the motor-evoked potential. The plasticity-inducing effects of rTMS in M1HAND show substantial inter......-individual variability which has been partially attributed to the val(66)met polymorphism in the brain-derived neurotrophic factor (BDNF) gene. Here we used theta burst stimulation (TBS) to examine whether the BDNF val(66)met genotype can be used to predict the expression of TBS-induced homeostatic metaplasticity in...... effects was modulated by the BDNF val(66)met polymorphism, our results do not support the notion that the BDNF val(66)met genotype is a major player with regard to TBS-induced plasticity and metaplasticity in the human M1HAND....

  9. Transcranial magnetic stimulation reveals two functionally distinct stages of motor cortex involvement during perception of emotional body language

    NARCIS (Netherlands)

    Borgomaneri, Sara; Gazzola, Valeria; Avenanti, Alessio

    2015-01-01

    Studies indicate that perceiving emotional body language recruits fronto-parietal regions involved in action execution. However, the nature of such motor activation is unclear. Using transcranial magnetic stimulation (TMS) we provide correlational and causative evidence of two distinct stages of mot

  10. Use of functional near-infrared spectroscopy to evaluate the effects of anodal transcranial direct current stimulation on brain connectivity in motor-related cortex

    Science.gov (United States)

    Yan, Jiaqing; Wei, Yun; Wang, Yinghua; Xu, Gang; Li, Zheng; Li, Xiaoli

    2015-04-01

    Transcranial direct current stimulation (tDCS) is a noninvasive, safe and convenient neuro-modulatory technique in neurological rehabilitation, treatment, and other aspects of brain disorders. However, evaluating the effects of tDCS is still difficult. We aimed to evaluate the effects of tDCS using hemodynamic changes using functional near-infrared spectroscopy (fNIRS). Five healthy participants were employed and anodal tDCS was applied to the left motor-related cortex, with cathodes positioned on the right dorsolateral supraorbital area. fNIRS data were collected from the right motor-related area at the same time. Functional connectivity (FC) between intracortical regions was calculated between fNIRS channels using a minimum variance distortion-less response magnitude squared coherence (MVDR-MSC) method. The levels of Oxy-HbO change and the FC between channels during the prestimulation, stimulation, and poststimulation stages were compared. Results showed no significant level difference, but the FC measured by MVDR-MSC significantly decreased during tDCS compared with pre-tDCS and post-tDCS, although the FC difference between pre-tDCS and post-tDCS was not significant. We conclude that coherence calculated from resting state fNIRS may be a useful tool for evaluating the effects of anodal tDCS and optimizing parameters for tDCS application.

  11. Motor cortex stimulation(MCS) for intractable complex regional pain syndrome (CRPS) type II: PSM analysis of Tc-99m ECD brain perfusion SPECT

    International Nuclear Information System (INIS)

    We had experienced a patient with intractable CRPS in whom statistical parametric mapping (SPM) analysis of cerebral perfusion explained the mechanism of pain control by MCS. A 43-year-old man presented spontaneous severe burning pain in his left hand and forearm and allodynia over the left arm and left hemibody. After the electrodes for neuromodulation therapy were inserted in the central sulcus, the baseline and stimulation brain perfusion SPECT using Tc-99m ECD were obtained within two days. The differences between the baseline and stimulation SPECT images, estimated at every voxel using t-statistics using SPM-99 software, were considered significant at a threshold of uncorrected P values less than 0.01. Among several areas significantly activated following pain relief with MCS, ipsilateral pyramidal tract in the cerebral peduncle might be related to the mechanism of pain control with MCS through efferent motor pathway. The result suggested that corticospinal neurons themselves or motor cortex efferent pathway maintained by the presence of intact corticospinal neurons could play an important role in producing pain control after MCS. This study would helpful in understanding of neurophysiology

  12. Spatial localization and distribution of the TMS-related 'hotspot' of the tibialis anterior muscle representation in the healthy and post-stroke motor cortex.

    Science.gov (United States)

    Sivaramakrishnan, Anjali; Tahara-Eckl, Lenore; Madhavan, Sangeetha

    2016-08-01

    Transcranial magnetic stimulation (TMS) is a type of noninvasive brain stimulation used to study corticomotor excitability of the intact and injured brain. Identification of muscle representations in the motor cortex is typically done using a procedure called 'hotspotting', which involves establishing the optimal location on the scalp that evokes a maximum TMS response with minimum stimulator intensity. The purpose of this study was to report the hotspot locations for the tibialis anterior (TA) muscle representation in the motor cortex of healthy and post stroke individuals. A retrospective data analyses from 42 stroke participants and 32 healthy participants was conducted for reporting TMS hotspot locations and their spatial patterns. Single pulse TMS, using a 110mm double cone coil, was used to identify the motor representation of the TA. The hotspot locations were represented as x and y-distances from the vertex for each participant. The mediolateral extent of the loci from the vertex (x-coordinate) and anteroposterior extent of the loci from the vertex (y-coordinate) was reported for each hemisphere: non-lesioned (XNLes, YNLes), lesioned (XLes, YLes) and healthy (XH, YH). We found that the mean hotspot loci for TA muscle from the vertex were approximately: 1.29cm lateral and 0.55cm posterior in the non-lesioned hemisphere, 1.25cm lateral and 0.5cm posterior in the lesioned hemisphere and 1.6cm lateral and 0.8cm posterior in the healthy brain. There was no significant difference in the x- and y-coordinates between the lesioned and non-lesioned hemispheres. However, the locations of the XNLes (p=0.01) and XLes (p=0.004) were significantly different from XH. The YNLes and YLes showed no significant differences from YH loci. Analyses of spatial clustering patterns using the Moran's I index showed a negative autocorrelation in stroke participants (NLes: Moran's I=-0.09, p<0.001; Les: Moran's I=-0.14, p=0.002), and a positive autocorrelation in healthy participants

  13. Training efficiency and transfer success in an extended real-time functional MRI neurofeedback training of the somato-motor cortex of healthy subjects

    Directory of Open Access Journals (Sweden)

    Tibor eAuer

    2015-10-01

    Full Text Available This study investigated the level of self-regulation of the somato-motor cortices (SMC attained by an extended functional MRI (fMRI neurofeedback training. Sixteen healthy subjects performed 12 real-time functional magnetic resonance imaging (rt-fMRI neurofeedback training sessions within 4 weeks, involving motor imagery of the dominant right as well as the non-dominant left hand. Target regions of interests in the SMC were individually localized prior to the training by overt finger movements. The feedback signal was defined as the difference between fMRI activation in the contra- and ipsilateral SMC and visually presented to the subjects. Training efficiency was determined by an off-line GLM analysis determining the fMRI percent signal changes in the somato-motor cortex (SMC target areas accomplished during the neurofeedback training. Transfer success was assessed by comparing the pre- and post-training transfer task, i.e. the neurofeedback paradigm without the presentation of the feedback signal. Group results show a distinct increase in feedback performance in the transfer task for the trained group compared to a matched untrained control group, as well as an increase in the time course of the training, indicating an efficient training and a successful transfer. Individual analysis revealed that the training efficiency was not only highly correlated to the transfer success but also predictive. Trainings with at least 12 efficient training runs were associated with a successful transfer outcome. A group analysis of the hemispheric contributions to the feedback performance showed that it is mainly driven by increased fMRI activation in the contralateral SMC, although some individuals relied on ipsilateral deactivation. Training and transfer results showed no difference between left and right hand imagery, with a slight indication of more ipsilateral deactivation in the early right hand trainings.

  14. A novel semi-immersive virtual reality visuo-motor task activates ventrolateral prefrontal cortex: a functional near-infrared spectroscopy study

    Science.gov (United States)

    Basso Moro, Sara; Carrieri, Marika; Avola, Danilo; Brigadoi, Sabrina; Lancia, Stefania; Petracca, Andrea; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina

    2016-06-01

    Objective. In the last few years, the interest in applying virtual reality systems for neurorehabilitation is increasing. Their compatibility with neuroimaging techniques, such as functional near-infrared spectroscopy (fNIRS), allows for the investigation of brain reorganization with multimodal stimulation and real-time control of the changes occurring in brain activity. The present study was aimed at testing a novel semi-immersive visuo-motor task (VMT), which has the features of being adopted in the field of neurorehabilitation of the upper limb motor function. Approach. A virtual environment was simulated through a three-dimensional hand-sensing device (the LEAP Motion Controller), and the concomitant VMT-related prefrontal cortex (PFC) response was monitored non-invasively by fNIRS. Upon the VMT, performed at three different levels of difficulty, it was hypothesized that the PFC would be activated with an expected greater level of activation in the ventrolateral PFC (VLPFC), given its involvement in the motor action planning and in the allocation of the attentional resources to generate goals from current contexts. Twenty-one subjects were asked to move their right hand/forearm with the purpose of guiding a virtual sphere over a virtual path. A twenty-channel fNIRS system was employed for measuring changes in PFC oxygenated-deoxygenated hemoglobin (O2Hb/HHb, respectively). Main results. A VLPFC O2Hb increase and a concomitant HHb decrease were observed during the VMT performance, without any difference in relation to the task difficulty. Significance. The present study has revealed a particular involvement of the VLPFC in the execution of the novel proposed semi-immersive VMT adoptable in the neurorehabilitation field.

  15. Transcranial magnetic stimulation with a half-sine wave pulse elicits direction-specific effects in human motor cortex

    Directory of Open Access Journals (Sweden)

    Jung Nikolai H

    2012-11-01

    Full Text Available Abstract Background Transcranial magnetic stimulation (TMS commonly uses so-called monophasic pulses where the initial rapidly changing current flow is followed by a critically dampened return current. It has been shown that a monophasic TMS pulse preferentially excites different cortical circuits in the human motor hand area (M1-HAND, if the induced tissue current has a posterior-to-anterior (PA or anterior-to-posterior (AP direction. Here we tested whether similar direction-specific effects could be elicited in M1-HAND using TMS pulses with a half-sine wave configuration. Results In 10 young participants, we applied half-sine pulses to the right M1-HAND which elicited PA or AP currents with respect to the orientation of the central sulcus. Measurements of the motor evoked potential (MEP revealed that PA half-sine stimulation resulted in lower resting motor threshold (RMT than AP stimulation. When stimulus intensity (SI was gradually increased as percentage of maximal stimulator output, the stimulus–response curve (SRC of MEP amplitude showed a leftward shift for PA as opposed to AP half-sine stimulation. Further, MEP latencies were approximately 1 ms shorter for PA relative to AP half-sine stimulation across the entire SI range tested. When adjusting SI to the respective RMT of PA and AP stimulation, the direction-specific differences in MEP latencies persisted, while the gain function of MEP amplitudes was comparable for PA and AP stimulation. Conclusions Using half-sine pulse configuration, single-pulse TMS elicits consistent direction-specific effects in M1-HAND that are similar to TMS with monophasic pulses. The longer MEP latency for AP half-sine stimulation suggests that PA and AP half-sine stimulation preferentially activates different sets of cortical neurons that are involved in the generation of different corticospinal descending volleys.

  16. Transcranial magnetic stimulation with a half-sine wave pulse elicits direction-specific effects in human motor cortex

    DEFF Research Database (Denmark)

    Jung, Nikolai H; Delvendahl, Igor; Pechmann, Astrid;

    2012-01-01

    Transcranial magnetic stimulation (TMS) commonly uses so-called monophasic pulses where the initial rapidly changing current flow is followed by a critically dampened return current. It has been shown that a monophasic TMS pulse preferentially excites different cortical circuits in the human motor...... hand area (M1-HAND), if the induced tissue current has a posterior-to-anterior (PA) or anterior-to-posterior (AP) direction. Here we tested whether similar direction-specific effects could be elicited in M1-HAND using TMS pulses with a half-sine wave configuration....

  17. Information about the weight of grasped objects from vision and internal models interacts within the primary motor cortex.

    Science.gov (United States)

    Loh, Morrison N; Kirsch, Louise; Rothwell, John C; Lemon, Roger N; Davare, Marco

    2010-05-19

    When grasping and lifting different objects, visual cues and previously acquired knowledge enable us to prepare the upcoming grasp by scaling the fingertip forces according to the actual weight of the object. However, when no visual information is available, the weight of the object has to be predicted based on information learned from previous grasps. Here, we investigated how changes in corticospinal excitability (CSE) and grip force scaling depend on the presence of visual cues and the weight of previously lifted objects. CSE was assessed by delivering transcranial magnetic stimulation (TMS) at different times before grasp of the object. In conditions in which visual information was not provided, the size of motor evoked potentials (MEP) was larger when the object lifted was preceded by a heavy relative to a light object. Interestingly, the previous lift also affected MEP amplitude when visual cues about object weight were available but only in the period immediately after object presentation (50 ms); this effect had already declined for TMS delivered 150 ms after presentation. In a second experiment, we demonstrated that these CSE changes are used by the motor system to scale grip force. This suggests that the corticospinal system stores a "sensorimotor memory" of the grasp of different objects and relies on this memory when no visual cues are present. Moreover, visual information about weight interacts with this stored representation and allows the corticospinal system to switch rapidly to a different model of predictive grasp control. PMID:20484640

  18. Suppression of EMG activity by subthreshold paired-pulse transcranial magnetic stimulation to the leg motor cortex.

    Science.gov (United States)

    Roy, François D

    2009-03-01

    Cortical activity driving a voluntary muscle contraction is inhibited by very low-intensity transcranial magnetic stimulation (TMS) and is reflected in the suppression of the average rectified EMG. This approach offers a method to test the contribution of cortical neurons actively involved in a motor task, but requires a large number of stimuli (approximately 100) to suitably depress the average EMG. Here, we investigated whether two pulses of subthreshold TMS at interstimulus intervals (ISIs) ranging between 1 and 12 ms could enhance the amount of EMG suppression in the tibialis anterior muscle compared to a single pulse. Pairs of subthreshold TMS at an ISI of 7 ms produced the maximum EMG suppression that was 42% more than the inhibition elicited using a single pulse. In addition, the signal-to-noise ratio of the TMS-induced suppression was further increased by a second pulse, delivered 7 ms later. The reduction in the EMG at the 7 ms paired-pulse interval occurred without any short-latency excitation suggesting that the two stimuli increased the activation of cortical inhibitory neurons. Subthreshold paired-pulse TMS at ISIs of 1-3 ms was prone to EMG excitation in the period that immediately preceded the inhibition and is consistent with the recruitment of short-interval intracortical facilitation (SICF). We propose that pairs of subthreshold TMS outside the range of SICF with an inter-pulse interval of 7 ms is optimal to inhibit ongoing cortical activity during human motor movement. PMID:19183971

  19. Reaching with the sixth sense: Vestibular contributions to voluntary motor control in the human right parietal cortex.

    Science.gov (United States)

    Reichenbach, Alexandra; Bresciani, Jean-Pierre; Bülthoff, Heinrich H; Thielscher, Axel

    2016-01-01

    The vestibular system constitutes the silent sixth sense: It automatically triggers a variety of vital reflexes to maintain postural and visual stability. Beyond their role in reflexive behavior, vestibular afferents contribute to several perceptual and cognitive functions and also support voluntary control of movements by complementing the other senses to accomplish the movement goal. Investigations into the neural correlates of vestibular contribution to voluntary action in humans are challenging and have progressed far less than research on corresponding visual and proprioceptive involvement. Here, we demonstrate for the first time with event-related TMS that the posterior part of the right medial intraparietal sulcus processes vestibular signals during a goal-directed reaching task with the dominant right hand. This finding suggests a qualitative difference between the processing of vestibular vs. visual and proprioceptive signals for controlling voluntary movements, which are pre-dominantly processed in the left posterior parietal cortex. Furthermore, this study reveals a neural pathway for vestibular input that might be distinct from the processing for reflexive or cognitive functions, and opens a window into their investigation in humans. PMID:26424179

  20. Primary motor cortex changes after amputation correlate with phantom limb pain and the ability to move the phantom limb.

    Science.gov (United States)

    Raffin, Estelle; Richard, Nathalie; Giraux, Pascal; Reilly, Karen T

    2016-04-15

    A substantial body of evidence documents massive reorganization of primary sensory and motor cortices following hand amputation, the extent of which is correlated with phantom limb pain. Many therapies for phantom limb pain are based upon the idea that plastic changes after amputation are maladaptive and attempt to normalize representations of cortical areas adjacent to the hand area. Recent data suggest, however, that higher levels of phantom pain are associated with stronger local activity and more structural integrity in the missing hand area rather than with reorganization of neighbouring body parts. While these models appear to be mutually exclusive they could co-exist, and one reason for the apparent discrepancy between them might be that no single study has examined the organisation of lip, elbow, and hand movements in the same participants. In this study we thoroughly examined the 3D anatomy of the central sulcus and BOLD responses during movements of the hand, elbow, and lips using MRI techniques in 11 upper-limb amputees and 17 healthy control subjects. We observed different reorganizational patterns for all three body parts as the former hand area showed few signs of reorganization, but the lip and elbow representations reorganized and shifted towards the hand area. We also found that poorer voluntary control and higher levels of pain in the phantom limb were powerful drivers of the lip and elbow topological changes. In addition to providing further support for the maladaptative plasticity model, we demonstrate for the first time that motor capacities of the phantom limb correlate with post-amputation reorganization, and that this reorganization is not limited to the face and hand representations but also includes the proximal upper-limb. PMID:26854561

  1. Excitability of the motor cortex ipsilateral to the moving body side depends on spatio-temporal task complexity and hemispheric specialization.

    Directory of Open Access Journals (Sweden)

    Femke E van den Berg

    Full Text Available Unilateral movements are mainly controlled by the contralateral hemisphere, even though the primary motor cortex ipsilateral (M1(ipsi to the moving body side can undergo task-related changes of activity as well. Here we used transcranial magnetic stimulation (TMS to investigate whether representations of the wrist flexor (FCR and extensor (ECR in M1(ipsi would be modulated when unilateral rhythmical wrist movements were executed in isolation or in the context of a simple or difficult hand-foot coordination pattern, and whether this modulation would differ for the left versus right hemisphere. We found that M1(ipsi facilitation of the resting ECR and FCR mirrored the activation of the moving wrist such that facilitation was higher when the homologous muscle was activated during the cyclical movement. We showed that this ipsilateral facilitation increased significantly when the wrist movements were performed in the context of demanding hand-foot coordination tasks whereas foot movements alone influenced the hand representation of M1(ipsi only slightly. Our data revealed a clear hemispheric asymmetry such that MEP responses were significantly larger when elicited in the left M1(ipsi than in the right. In experiment 2, we tested whether the modulations of M1(ipsi facilitation, caused by performing different coordination tasks with the left versus right body sides, could be explained by changes in short intracortical inhibition (SICI. We found that SICI was increasingly reduced for a complex coordination pattern as compared to rest, but only in the right M1(ipsi. We argue that our results might reflect the stronger involvement of the left versus right hemisphere in performing demanding motor tasks.

  2. Pharmacological modulation of the short-lasting effects of antagonistic direct current-stimulation over the human motor cortex

    Directory of Open Access Journals (Sweden)

    Leila eChaieb

    2012-07-01

    Full Text Available Combined administration of transcranial direct current stimulation (tDCS with either pergolide (PGL or D-cycloserine (D-CYC can prolong the excitability-diminishing effects of cathodal, or the excitability enhancing effect of anodal stimulation for up to 24hrs poststimulation. However, it remains unclear whether the potentiation of the observed aftereffects is dominated by the polarity and duration of the stimulation, or the dual application of combined stimulation and drug administration. The present study looks at whether the aftereffects of oral administration of PGL (a D1/D2 agonist or D-CYC (a partial NMDA receptor agonist, in conjunction with the short duration antagonistic application of tDCS (either 5 min cathodal followed immediately by 5 min anodal or vice versa, that alone only induces short lasting aftereffects, can modulate cortical excitability in healthy human subjects, as revealed by a single-pulse MEP (motor-evoked-potential paradigm. Results indicate that the antagonistic application of DC currents induces short-term neuroplastic aftereffects that are dependent upon the polarity of the second application of short-duration tDCS. The application of D-cycloserine resulted in a reversal of this trend and so consequently a marked inhibition of cortical excitability with the cathodal-anodal stimulation order was observed. The administration of pergolide showed no significant aftereffects in either case. These results emphasise that the aftereffects of tDCS are dependent upon the stimulation orientation, and mirror the findings of other studies reporting the neuroplasticity inducing aftereffects of tDCS, and their prolongation when combined with the administration of CNS active drugs.

  3. Moving mirrors: a high-density EEG study investigating the effect of camera movements on motor cortex activation during action observation.

    Science.gov (United States)

    Heimann, Katrin; Umiltà, Maria Alessandra; Guerra, Michele; Gallese, Vittorio

    2014-09-01

    Action execution-perception links (mirror mechanism) have been repeatedly suggested to play crucial roles in social cognition. Remarkably, the designs of most studies exploring this topic so far excluded even the simplest traces of social interaction, such as a movement of the observer toward another individual. This study introduces a new design by investigating the effects of camera movements, possibly simulating the observer's own approaching movement toward the scene. We conducted a combined high-density EEG and behavioral study investigating motor cortex activation during action observation measured by event-related desynchronization and resynchronization (ERD/ERS) of the mu rhythm. Stimuli were videos showing a goal-related hand action filmed while using the camera in four different ways: filming from a fixed position, zooming in on the scene, approaching the scene by means of a dolly, and approaching the scene by means of a steadycam. Results demonstrated a consistently stronger ERD of the mu rhythm for videos that were filmed while approaching the scene with a steadycam. Furthermore, videos in which the zoom was applied reliably demonstrated a stronger rebound. A rating task showed that videos in which the camera approached the scene were felt as more involving and the steadycam was most able to produce a visual experience close to the one of a human approaching the scene. These results suggest that filming technique predicts time course specifics of ERD/ERS during action observation with only videos simulating the natural vision of a walking human observer eliciting a stronger ERD than videos filmed from a fixed position. This demonstrates the utility of ecologically designed studies for exploring social cognition. PMID:24666130

  4. Integration of BOLD-fMRI and DTI into radiation treatment planning for high-grade gliomas located near the primary motor cortexes and corticospinal tracts

    International Nuclear Information System (INIS)

    The main objective of this study was to evaluate the efficacy of integrating the blood oxygen level dependent functional magnetic resonance imaging (BOLD-fMRI) and diffusion tensor imaging (DTI) data into radiation treatment planning for high-grade gliomas located near the primary motor cortexes (PMCs) and corticospinal tracts (CSTs). A total of 20 patients with high-grade gliomas adjacent to PMCs and CSTs between 2012 and 2014 were recruited. The bilateral PMCs and CSTs were located in the normal regions without any overlapping with target volume of the lesions. BOLD-fMRI, DTI and conventional MRI were performed on patients (Karnofsky performance score ≥ 70) before radical radiotherapy treatment. Four different imaging studies were conducted in each patient: a planning computed tomography (CT), an anatomical MRI, a DTI and a BOLD-fMRI. For each case, three treatment plans (3DCRT, IMRT and IMRT-PMC&CST) were developed by 3 different physicists using the Pinnacle planning system. Our study has shown that there was no significant difference between the 3DCRT and IMRT plans in terms of dose homogeneity, but IMRT displayed better planning target volume (PTV) dose conformity. In addition, we have found that the Dmax and Dmean to the ipsilateral and contralateral PMC and CST regions were considerably decreased in IMRT-PMC&CST group (p < 0.001). In conclusion, integration of BOLD-fMRI and DTI into radiation treatment planning is feasible and beneficial. With the assistance of the above-described techniques, the bilateral PMCs and CSTs adjacent to the target volume could be clearly marked as OARs and spared during treatment

  5. Cat Scan

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> A man takes his motionless dog to the vet."Doc,I think my dog is dead.”The vet looks the dog over, goes into a backroom,and comes out with a cat.He places the caton the table next to the dog.The cat walks aroundand sniffs at the dog.The dog does not move.The

  6. Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil, Krill Oil, and Algal Biomass.

    Science.gov (United States)

    Polotow, Tatiana G; Poppe, Sandra C; Vardaris, Cristina V; Ganini, Douglas; Guariroba, Maísa; Mattei, Rita; Hatanaka, Elaine; Martins, Maria F; Bondan, Eduardo F; Barros, Marcelo P

    2015-10-01

    Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions. PMID:26426026

  7. Redox Status and Neuro Inflammation Indexes in Cerebellum and Motor Cortex of Wistar Rats Supplemented with Natural Sources of Omega-3 Fatty Acids and Astaxanthin: Fish Oil, Krill Oil, and Algal Biomass

    Directory of Open Access Journals (Sweden)

    Tatiana G. Polotow

    2015-09-01

    Full Text Available Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs and the antioxidant carotenoid astaxanthin (ASTA. However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation, drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.

  8. Motor Priming in Neurorehabilitation

    OpenAIRE

    Stoykov, Mary Ellen; Madhavan, Sangeetha

    2015-01-01

    Priming is a type of implicit learning wherein a stimulus prompts a change in behavior. Priming has been long studied in the field of psychology. More recently, rehabilitation researchers have studied motor priming as a possible way to facilitate motor learning. For example, priming of the motor cortex is associated with changes in neuroplasticity that are associated with improvements in motor performance. Of the numerous motor priming paradigms under investigation, only a few ...

  9. Cerebellum and motor learning, motor memory and motor integration: morphology and distribution of neuropeptide Y neurons in rat cerebellar cortex%大鼠小脑皮质内神经肽Y能神经元的形态与分布小脑的运动学习、记忆及整合功能

    Institute of Scientific and Technical Information of China (English)

    王省; 孙银平; 蔡新华

    2005-01-01

    BACKGROUND: Neuropeptide Y (NPY) neurons are extensively located in various brain regions such as cerebral cortex, caudate-putamen nucleus, syslimbic system, thalamus and brain stem. They are also involved in various brain activities such as motor learning, motor memory and motor integration. Considering the fact that cerebellum can reorganize through motor learning, we tried to identify the morphology and distribution of NPY neurons in rat's cerebellar cortex to obtain the morphologic knowledge that is related to its cerebellar-cortex-based motor learning.OBJECTIVE: To investigate the morphology and distribution of NPY -immunoreactive neurons in rat's cerebellar cortex, and discuss the relationship between NPY neurons and cerebellum motor learning and motor memory.DESIGN: A single-sample-study based on animal samples.SETTING: Anatomy Department, Pathophysiology Department and Morphology Center in Xinxiang Medical College.MATERIALS: From July to December 2001, the experiment was performed at the Morphology Center in Xinxiang Medical College. Ten Sprague-Dawley (SD) rats, clean grade, regardless of their gender and weighing 100-200 g,were selected.METHODS: After intraperitoneal injection anesthesia and ascending aorta infusion fixation, the cerebellum was taken out by craniosurgery. The cerebellum was immersed in the same fixative fluid for duration of 48 hours, and then was embedded in paraffin. The next step was to make continuous sagittal sections. NPY neurons were identified by SP immunohistochemical staining, using rats cerebral section as the positive control. In the negative control, the first antibody replaced by Bovine Calf Serum(BCS), and the second antibody replaced by 0.01 mol/L PBS. Sequentially the light-microscopic observation and micrography were recorded.MAIN OUTCOME MEASUREMENTS: The Morphology and distribution of NPY neurons in rat's cerebellar cortex were taken as main outcome measurements.RESULTS: NPY-immunoreactive neurons were distributed in

  10. Cat scratch disease (image)

    Science.gov (United States)

    Cat scratch disease is an infectious illness associated with cat scratches, bites, or exposure to cat saliva, causing chronic swelling of the lymph nodes. Cat scratch disease is possibly the most common cause of ...

  11. Decoding of rat's primary motor cortex by partial least square%基于偏最小二乘的大鼠初级运动皮层解码

    Institute of Scientific and Technical Information of China (English)

    朱凡; 李悦; 蒋凯; 叶树明; 郑筱祥

    2013-01-01

    为了准确解析大鼠初级运动皮层神经元发放模式并预测相应的肢体动作,实验同时记录大鼠初级运动皮层神经元峰电位发放和大鼠前肢压力,利用K均值法和主成分分析法对神经元进行分类,采用偏最小二乘分析大鼠初级运动皮层神经元活动与前肢运动参数之间的关系,并对该解码结果与维纳滤波和卡尔曼滤波算法的解码结果进行比较.实验结果表明:神经元的发放活动在压杆前0.6s开始有增加的趋势,提示大鼠的初级运动皮层神经元分布式活动可用于大鼠前肢运动的解析和预测,且偏最小二乘解码得到的预测值与真实压杆值的相关系数在0.85以上,均高于维纳滤波和卡尔曼滤波的解码结果.%In order to analytizing neurons release pattern of the primary motor cortex of rats accurately and predicting corresponding body movement,the activities of the neurons ensemble spike activities in rat's primary motor cortex and the forelimb pressure were recorded simultaneously in the experiment.K-means and principal component analysis were used to classification of neurons,then the partial least squares was used to analyze the relations between the neurons activities of the primary motor cortex of the rat and the forelimb motion parameters,and the results were compared with Wiener filter and Kalman filter.The experimental results indicate that the activities of neurons ensembles began a trend of increase O.6 second before lever pressing,Which hints the neurons distributed activities of the primary motor cortex in rats can be used to analysis and prediction its forelimb movement and the correlation coefficient between the predicted value and real pressure value is more than 0.85 using the partial least squares,with a better decoding results than those using the Wiener filtering and Kalman filtering.

  12. Cat's Claw

    Science.gov (United States)

    ... R S T U V W X Y Z Cat's Claw Share: On This Page Introduction What the ... More Information Key References © Steven Foster Common Names: cat’s claw, uña de gato Latin Name: Uncaria tomentosa, ...

  13. [Changes in the excitability of motor neurons and synaptic effects on them during formation of the generator of scratching movements in the cat].

    Science.gov (United States)

    Zavadskaia, T V; Degtiarenko, A M; Baev, K V

    1987-01-01

    It is shown that the state of the segmental apparatus of the lumbal spinal cord of immobilized intercollicularly decerebrated cats during formation of a scratching generator is essentially different from that of a spinal animal. The excitability of "aiming" and "scratching" motoneurons increases, recurrent and reciprocal Ia inhibition of motoneurons becomes stronger and influence of Ib afferents weaker. The flexor reflex afferents exert inhibitory influences on "aiming" motoneurons. After spinalization these influences become excitatory, and the inhibitory influences on "scratching" motoneurons become weaker. The functional role of described changes is discussed. PMID:3110635

  14. A Catalogue of Anatomical Fugitive Sheets: Cat. 49-62

    OpenAIRE

    1999-01-01

    Images Cat. 50 Cat. 51 Cat. 53 Cat. 54 Cat. 55 (a) Cat. 55 (b) Cat. 56 Cat. 57: 1 Cat. 57: 2 Cat. 57: 3 Cat. 57: 4 Cat. 59: 1 Cat. 59: 2 Cat. 59: 3 Cat. 59: 4 Cat. 60 Cat. 61 Cat. 62: 1 (a) Cat. 62: 1 (b) Cat. 62: 2 (a) Cat. 62: 2 (b)

  15. A Catalogue of Anatomical Fugitive Sheets: Cat. 26-48

    OpenAIRE

    1999-01-01

    Images Cat. 26: 1 (a) Cat. 26: 1 (b) Cat. 26: 2 (a) Cat. 26: 2(b) Cat. 27: 1 (a) Cat. 27: 1 (b) Cat. 27: 2 (a) Cat. 27: 2 (b) Cat. 28 Cat. 29: 2 (a) Cat. 29: 2 (b) Cat. 30: 1 Cat. 30: 2 Cat. 30: 3 Cat. 33 Cat. 34: 1 Cat. 34: 2 Cat. 35: 1 Cat. 35: 2 Cat. 35: 3 Cat. 36 Cat. 37 Cat. 38: 1 Cat. 38: 2 Cat. 40 Cat. 42 Cat. 43 Cat. 44 Cat. 45: 1 Cat. 45: 2 Cat. 46 Cat. 47: 1 Cat. 47: 2 Cat. 47: 3 Cat. 48: 1 Cat. 48: 2 Cat. 48: 3

  16. Functional differentiation of the premotor cortex: Behavioural and brain imaging studies in humans

    OpenAIRE

    Potgieser, Adriaan Remco Ewoud

    2015-01-01

    The premotor cortex is a brain structure that is involved in the preparation of movements. It has an important role in the final integration of task-related information and to funnel this to the primary motor cortex, which subsequently causes the execution of a movement. Premotor areas can also influence motor output through their direct interactions with both the spinal cord. Within the premotor cortex, the ventral premotor cortex (PMv), dorsal premotor cortex (PMd) and supplementary motor a...

  17. 基于Cortex-M3内核MCU的BLDCM控制器研究%Research of Brushless DC Motor Controller Based on MCU of CortexTM-M3 Kernel

    Institute of Scientific and Technical Information of China (English)

    欧卫斌

    2011-01-01

    Cortex-M3内核32位高性能MCU设计一款通用性、控制性较好,性价比较高的BLDCM控制器.根据BLDCM的工作原理和MCU的良好性能进行了详细设计.实现了对BLDCM的转速、电流双闭环控制,通过实验测试了控制器的各项性能.该款基于32位MCU的控制器性能良好,结构紧凑,性价比高,具有较高实用价值.结合应用经验发现,API函数支持下Cortex-M3内核的MCU在硬件控制和软件编程方面较以往单片机等具有优势,基于API函数支持的MCU应用将是未来趋势.%A high generality, better controllable performance and high cost performance BLDCM controller with 32 bit high-performance MCU of Cortex?-M3 kernel was designed according to the working principles of BLDCM and the good performance of LM3S615. The speed and current double closed-loop control of BLDCM was realized after testing the performance of the controller. This controller based on the low power consumption 32 bit MCU has excellent performances, such as compact structure, high cost performance and high practical value. In combination with the application experience, it is found that ARM Cortex?-M3 Processor kernel MCU supported by API function is better than the common single chip microcomputer in the aspects of the hardware control and the software programming. The application of MCU supported by API function has a bright prospect.

  18. An evoked potential mapping of transcallosal projections in the cat

    Directory of Open Access Journals (Sweden)

    A. Cukiert

    1989-03-01

    Full Text Available In ten adult cats anesthetized with ketamine hydrochloride the neocortex was exposed and rectangular pulses (1msec, 0.5 Hz and variable intensity were applied to discrete points of one side and transcallosal evoked potentials were recorded from the other. The stimulation and recording positions were determined on a cartesian map of most of the exposable neocortical areas and the potentials were analysed as to their components, voltage and latency. Passive spread and electrotonic potentials and the effects of increasing frequency were also analysed. The results showed large transcallosal potentials in some areas and an increase of potentials in the caudorostral direction, attaining the highest values in anteromedial areas of the suprasylvian gyrus. Confirming anatomical studies, a few silent spots were found in the motor and somesthetic cortex and in restricted posterior regions of the visual cortex, where small or zero voltages occurred. While causing weak contralateral potentials, stimulation of some posterior sites provoked high voltage potentials in anterior regions of the side being stimulated and in the corresponding area of the opposite site. These posterior sites are. poorly interconnected by the corpus callosum. The L-shaped indirect connection described in this work may be involved in some types of epilepsy and may explain the effectiveness of partial callosotomy in their treatment.

  19. Cerebral cortex modulation of pain

    Institute of Scientific and Technical Information of China (English)

    Yu-feng XIE; Fu-quan HUO; Jing-shi TANG

    2009-01-01

    Pain is a complex experience encompassing sensory-discriminative, affective-motivational and cognitiv e-emotional com-ponents mediated by different mechanisms. Contrary to the traditional view that the cerebral cortex is not involved in pain perception, an extensive cortical network associated with pain processing has been revealed using multiple methods over the past decades. This network consistently includes, at least, the anterior cingulate cortex, the agranular insular cortex, the primary (SⅠ) and secondary somatosensory (SⅡ) cortices, the ventrolateral orbital cortex and the motor cortex. These corti-cal structures constitute the medial and lateral pain systems, the nucleus submedius-ventrolateral orbital cortex-periaque-ductal gray system and motor cortex system, respectively. Multiple neurotransmitters, including opioid, glutamate, GABA and dopamine, are involved in the modulation of pain by these cortical structures. In addition, glial cells may also be in-volved in cortical modulation of pain and serve as one target for pain management research. This review discusses recent studies of pain modulation by these cerebral cortical structures in animals and human.

  20. Schroedinger's cat

    International Nuclear Information System (INIS)

    The issue is to seek quantum interference effects in an arbitrary field, in particular in psychology. For this a digest of quantum mechanics over finite-n-dimensional Hilbert space is invented. In order to match crude data not only von Neumann's mixed states are used but also a parallel notion of unsharp tests. The mathematically styled text (and earlier work on multibin tests, designated MB) deals largely with these new tests. Quantum psychology itself is only given a foundation. It readily engenders objections; its plausibility is developed gradually, in interlocking essays. There is also the empirically definite proposal that (state, test, outcome)-indexed counts be gathered to record data, then fed to a 'matrix format' (MF) search for quantum models. A previously proposed experiment in visual perception which has since failed to find significant quantum correlations, is discussed. The suspicion that quantum mechanics is all around goes beyond MF, and 'Schroedinger's cat' symbolizes this broader perspective. (author)

  1. The functional alterations associated with motor imagery training: a comparison between motor execution and motor imagery of sequential finger tapping

    Science.gov (United States)

    Zhang, Hang; Yao, Li; Long, Zhiying

    2011-03-01

    Motor imagery training, as an effective strategy, has been more and more applied to mental disorders rehabilitation and motor skill learning. Studies on the neural mechanism underlying motor imagery have suggested that such effectiveness may be related to the functional congruence between motor execution and motor imagery. However, as compared to the studies on motor imagery, the studies on motor imagery training are much fewer. The functional alterations associated with motor imagery training and the effectiveness of motor imagery training on motor performance improvement still needs further investigation. Using fMRI, we employed a sequential finger tapping paradigm to explore the functional alterations associated with motor imagery training in both motor execution and motor imagery task. We hypothesized through 14 consecutive days motor imagery training, the motor performance could be improved and the functional congruence between motor execution and motor imagery would be sustained form pre-training phase to post-training phase. Our results confirmed the effectiveness of motor imagery training in improving motor performance and demonstrated in both pre and post-training phases, motor imagery and motor execution consistently sustained the congruence in functional neuroanatomy, including SMA (supplementary motor cortex), PMA (premotor area); M1( primary motor cortex) and cerebellum. Moreover, for both execution and imagery tasks, a similar functional alteration was observed in fusiform through motor imagery training. These findings provided an insight into the effectiveness of motor imagery training and suggested its potential therapeutic value in motor rehabilitation.

  2. Cat and Dog Bites

    Science.gov (United States)

    MENU Return to Web version Cat and Dog Bites Cat and Dog Bites How should I take care of a bite from a cat or a dog? Whether from a family pet or a neighborhood stray, cat and dog bites are common. Here are some things you ...

  3. Increase in Short-Interval Intracortical Facilitation of the Motor Cortex after Low-Frequency Repetitive Magnetic Stimulation of the Unaffected Hemisphere in the Subacute Phase after Stroke

    OpenAIRE

    Eduardo Arruda Mello; Cohen, Leonardo G; Sarah Monteiro dos Anjos; Juliana Conti; Karina Nocelo F. Andrade; Fernanda Tovar Moll; Theo Marins; Corina A. Fernandes; Waldyr Rodrigues; Adriana Bastos Conforto

    2015-01-01

    Low-frequency repetitive transcranial magnetic stimulation of the unaffected hemisphere (UH-LF-rTMS) in patients with stroke can decrease interhemispheric inhibition from the unaffected to the affected hemisphere and improve hand dexterity and strength of the paretic hand. The objective of this proof-of-principle study was to explore, for the first time, effects of UH-LF-rTMS as add-on therapy to motor rehabilitation on short-term intracortical inhibition (SICI) and intracortical facilitation...

  4. Neuronavigation Increases the Physiologic and Behavioral Effects of Low-Frequency rTMS of Primary Motor Cortex in Healthy Subjects

    OpenAIRE

    Bashir, S.; Edwards, D; Pascual-Leone, A

    2010-01-01

    Low-frequency repetitive transcranial magnetic stimulation (rTMS) can exert local and inter-hemispheric neuromodulatory effects on cortical excitability. These physiologic effects can translate into changes in motor behavior, and may offer valuable therapeutic interventions in recovery from stroke. Neuronavigated TMS can maximize accurate and consistent targeting of a given cortical region, but is a lot more involved that conventional TMS. We aimed to assess whether neuronavigation enhances t...

  5. 共济失调患者手运动时脑激活区域的定量分析%Quantitative analysis of the hand motor cortex in ataxia patients using blood oxygen level dependent functional magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    元小冬; 王小洁; 王德; 赵丽君; 王守红

    2010-01-01

    Objective To study the characteristics of the hand motor cortex in ataxia patients during active and passive finger-to-thumb opposition movements using bold oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI). Methods Ten right-handed healthy volunteers and 16 ataxia patients with motor cortex lesions were selected, and whole-brain BOLD-fMRI examinations were made while the subjects were performing the active and passive movements. Activated volume and intensity were recorded from the corresponding motor cortex and analyzed quantitatively. Meanwhile, the patients' coordination was evaluated using the international cooperative ataxia rating scale (ICARS). Results During passive movement of the ataxia patient's affected hands, the ipsilateral supplementary motor area (SMA) activated volume was larger than that during normal ipsilateral hand movement, and the activation intensity was also higher than that in the healthy controls. The ipsilateral cerebellum activated volume and intensity were significantly lower than those in the control group, and the frequency of appearance of the cerebellum was also less. The patients' activated volume and intensity in the ipsilateral cerebellum showed no correlation with ICARS scores. Conclusions When the ataxia patients' affected side cerebellum was dysfunctional, the ipsilateral SMA could compensate for the weak cerebellum function. The ICARS does not reflect cerebellum function.%目的 利用血氧水平依赖性功能性磁共振成像(BOLD-fMRI)技术,探讨共济失调患者在主动与被动复杂对指运动模式下关键脑功能区激活体积和强度的变化.方法 选取共济失调患者16例作为病例组,另选10名健康志愿者作为正常组.入选者均进行主动与被动复杂对指运动,在这两种运动模式下进行BOLD-fMRl检查,记录相应脑运动功能区的激活体积和强度并进行定量分析.采用共济失调量表(ICARS)对共济失调患者的

  6. Functional rearrangement of the primary and secondary motor cortex in patients with primary tumors of the central nervous system located in the region of the central sulcus depending on the histopathological type and the size of tumor: Examination by means of functional magnetic resonance imaging

    International Nuclear Information System (INIS)

    The aim of this study was to analyze the reorganization of the centers of the motor cortex in patients with primary neuroepithelial tumors of the central nervous system (CNS) located in the region of the central sulcus in relation to the histopathological type and the size of tumor, as determined by means of functional magnetic resonance imaging (fMRI). The fMRI was performed prior to the surgical treatment of patients with tumors located in the region of the central sulcus (WHO stage I and II, n=15; WHO stage III and IV, n=25). The analysis included a record of the activity in the areas of the primary motor cortex (M1) and the secondary motor cortex: the premotor cortex (PMA) and the accessory motor area (SMA). The results were correlated with the histopathological type of the tumor and its size expressed in cm3. The frequency of activation of the motor center was higher in the group of patients who had less aggressive tumors, such as low-grade glioma (LGG), as well as in tumors of lower volume, and this was true both for the hemisphere where the tumor was located and in the contralateral one. Mean values of t-statistics of activation intensity, mean numbers of activated clusters, and their ranges were lower in all analyzed motor areas of LGG tumors. The values of t-statistics and activation areas were higher in the case of small tumors located in ipsilateral centers, and in large tumors located in contralateral centers, aside from the SMA area where the values of t-statistics were equal for both groups. The contralateral SMA area was characterized by the highest stability of all examined centers of secondary motor cortex. No significant association (p>0.05) was observed between the absolute value of the mean registered activity (t-statistics) and the size of examined areas (number of clusters) when the groups were stratified with regards to the analyzed parameters. The presence of a neoplastic lesion, its histopathological type and finally its size modulate the

  7. Suppression of phase synchronisation in network based on cat's brain

    Science.gov (United States)

    Lameu, Ewandson L.; Borges, Fernando S.; Borges, Rafael R.; Iarosz, Kelly C.; Caldas, Iberê L.; Batista, Antonio M.; Viana, Ricardo L.; Kurths, Jürgen

    2016-04-01

    We have studied the effects of perturbations on the cat's cerebral cortex. According to the literature, this cortex structure can be described by a clustered network. This way, we construct a clustered network with the same number of areas as in the cat matrix, where each area is described as a sub-network with a small-world property. We focus on the suppression of neuronal phase synchronisation considering different kinds of perturbations. Among the various controlling interventions, we choose three methods: delayed feedback control, external time-periodic driving, and activation of selected neurons. We simulate these interventions to provide a procedure to suppress undesired and pathological abnormal rhythms that can be associated with many forms of synchronisation. In our simulations, we have verified that the efficiency of synchronisation suppression by delayed feedback control is higher than external time-periodic driving and activation of selected neurons of the cat's cerebral cortex with the same coupling strengths.

  8. Cat Scratch Disease

    Science.gov (United States)

    Cat scratch disease (CSD) is an illness caused by the bacterium Bartonella henselae. Almost half of all cats carry the infection ... symptoms of CSD, call your doctor. Centers for Disease Control and Prevention

  9. Cat Scratch Disease

    Science.gov (United States)

    Cat scratch disease (CSD) is an illness caused by the bacterium Bartonella henselae. Almost half of all cats carry the infection at some ... Poor appetite For people with weak immune systems, CSD may cause more serious problems. The best way ...

  10. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Snowboarding, Skating Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  11. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Here's Help White House Lunch Recipes Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  12. Discospondylitis in a cat

    International Nuclear Information System (INIS)

    The incidence and causative agents of discospondylitis in cats are unknown. This report describes a cat with radiologic changes consistent with discospondylitis and concurrent urinary tract infection. As in dogs, discospondylitis should be the primary rule out for vertebral end plate lysis in cats

  13. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that ...

  14. Relationship between the velocity of illusory hand movement and strength of MEG signals in human primary motor cortex and left angular gyrus.

    Science.gov (United States)

    Casini, Laurence; Roll, Jean-Pierre; Romaiguère, Patricia

    2008-03-01

    We studied the relationship between the velocity of movement illusion and the activity level of primary motor area (M1) and of the left angular gyrus (AG) in humans. To induce illusory movement perception, we applied co-vibration at different frequencies on tendons of antagonistic muscle groups. Since it is well established that the velocity of illusory movement is related to the difference in vibration frequency applied to two antagonistic muscles, we compared magnetoencephalography (MEG) signals recorded in two conditions of co-vibration: in the "fast illusion" condition a frequency difference of 80 Hz was applied on the tendons of the right wrist extensor and flexor muscle groups, whereas in the "slow illusion" condition a frequency difference of 40 Hz was applied on the same muscle groups. The dipole strength, reflecting the activity level of structures, was measured over M1 and the left AG in two different time-periods: 0-400 and 400-800 ms in each condition. Our results showed that the activity level of the AG was similar in both conditions whatever the time-period, whereas the activity level of M1 was higher in the "fast illusion" condition compared to the "slow illusion" condition from 400 ms after the vibration onset only. The data suggest that the two structures differently contributed to the perception of illusory movements. Our hypothesis is that M1 would be involved in the coding of cinematic parameters of the illusory movement but not the AG. PMID:18317743

  15. Adiponectin mRNA Expression in the Cat (Felis domesticus

    Directory of Open Access Journals (Sweden)

    Angela L. Lusby

    2010-01-01

    Full Text Available Problem statement: Adiponectin is a hormone expressed from adipose tissue in people, rodents and dogs. Adiponectin has anti-inflammatory action with beneficial effects on cardiovascular health and insulin sensitivity. With increasing fat mass, adiponectin concentrations paradoxically decrease. Adiponectin’s role in metabolism and diabetes mellitus is of interest in feline medicine because cats are susceptible to developing type II diabetes with weight gain. This study determined relative amounts of adiponectin mRNA expression from various body tissues and organs in domestic cats. Approach: Two intact male cats and one intact female cat were evaluated post-mortem. All cats were estimated to be young adults and had lean body conditions. Tissues samples from inguinal subcutaneous adipose, visceral mesenteric adipose, liver, skeletal muscle, cardiac muscle, aorta, stomach fundus, duodenum, pancreas, thyroid gland, adrenal gland (cortex and medulla and renal cortex were collected and frozen. Following RNA extraction, adiponectin mRNA expression of each tissue was detected using Reverse Transcriptase (RT real-time (Q PCR. Results: Visceral adipose tissue had the highest level of expression, averaging 12% higher than subcutaneous adipose. All other tissues had negligible levels of expression compared to adipose samples. Conclusion: This study provided a valuable step for adiponectin research in cats by determining which tissues express this hormone. Cats differ from human beings by expressing higher levels of adiponectin in visceral compared to subcutaneous fat. The metabolic impact of this expression pattern is not known and provides a basis for future research.

  16. Pulmonary thromboembolism in cats.

    Science.gov (United States)

    Schermerhorn, Thomas; Pembleton-Corbett, Julie R; Kornreich, Bruce

    2004-01-01

    Pulmonary thromboembolism (PTE) is rarely diagnosed in cats, and the clinical features of the disease are not well known. PTE was diagnosed at postmortem examination in 17 cats, a prevalence of 0.06% over a 24-year period. The age of affected cats ranged from 10 months to 18 years, although young (10 years) cats were more commonly affected than were middle-aged cats. Males and females were equally affected. The majority of cats with PTE (n = 16) had concurrent disease, which was often severe. The most common diseases identified in association with PTE were neoplasia, anemia of unidentified cause, and pancreatitis. Cats with glomerulonephritis, encephalitis, pneumonia, heart disease, and hepatic lipidosis were also represented in this study. Most cats with PTE demonstrated dyspnea and respiratory distress before death or euthanasia, but PTE was not recognized ante mortem in any cat studied. In conclusion, PTE can affect cats of any age and is associated with a variety of systemic and inflammatory disorders. It is recommended that the same clinical criteria used to increase the suspicion of PTE in dogs should also be applied to cats. PMID:15320593

  17. A Catalogue of Anatomical Fugitive Sheets: Cat. 1-10

    OpenAIRE

    1999-01-01

    Images Cat. 1 Cat. 2 (a) Cat. 2 (b) Cat. 2 (c) Cat. 2 (d) Cat. 2 (e) Cat. 2 (f) Cat. 3: 1 (a) Cat. 3: 1 (b) Cat. 3: 2 (a) Cat. 3: 2 (b) Cat. 4: 1 Cat. 4: 2 Cat. 6: 1 (a) Cat. 6: 1 (b) Cat. 6: 2 (a) Cat. 6: 2 (b) Cat. 7: 1 (a) Cat. 7: 1 (b) Cat. 7: 2 (a) Cat. 7: 2 (b) Cat. 8: 1 Cat. 9: 1 Cat. 9: 2 Cat. 10: 1 Cat. 10: 2

  18. Effects of the Bee Venom Herbal Acupuncture on the Neurotransmitters of the Rat Brain Cortex

    Directory of Open Access Journals (Sweden)

    Hyoung-Seok Yun

    2001-02-01

    Full Text Available In order to study the effects of bee venom Herbal Acupuncture on neurotransmitters in the rat brain cortex, herbal acupuncture with bee venom group and normal saline group was performed at LI4 bilaterally of the rat. the average optical density of neurotransmitters from the cerebral cortex was analysed 30 minutes after the herbal aqupuncture, by the immunohistochemistry. The results were as follows: 1. The density of NADPH-diaphorase in bee venom group was increased significantly at the motor cortex, visual cortex, auditory cortex, cingulate cortex, retrosplenial cortex and perirhinal cortex compared to the normal saline group. 2. The average optical density of vasoactive intestinal peptide in bee venom group had significant changes at the insular cortex, retrosplenial cortex and perirhinal cortex, compared to the normal saline group. 3. The average optical density of neuropeptide-Y in bee venom group increased significantly at the visual cortex and cingulate cortex, compared to the normal saline group.

  19. Canonical computations of cerebral cortex.

    Science.gov (United States)

    Miller, Kenneth D

    2016-04-01

    The idea that there is a fundamental cortical circuit that performs canonical computations remains compelling though far from proven. Here we review evidence for two canonical operations within sensory cortical areas: a feedforward computation of selectivity; and a recurrent computation of gain in which, given sufficiently strong external input, perhaps from multiple sources, intracortical input largely, but not completely, cancels this external input. This operation leads to many characteristic cortical nonlinearities in integrating multiple stimuli. The cortical computation must combine such local processing with hierarchical processing across areas. We point to important changes in moving from sensory cortex to motor and frontal cortex and the possibility of substantial differences between cortex in rodents vs. species with columnar organization of selectivity. PMID:26868041

  20. Two different motor systems are needed to generate human speech.

    Science.gov (United States)

    Holstege, Gert; Subramanian, Hari H

    2016-06-01

    Vocalizations such as mews and cries in cats or crying and laughter in humans are examples of expression of emotions. These vocalizations are generated by the emotional motor system, in which the mesencephalic periaqueductal gray (PAG) plays a central role, as demonstrated by the fact that lesions in the PAG lead to complete mutism in cats, monkeys, as well as in humans. The PAG receives strong projections from higher limbic regions and from the anterior cingulate, insula, and orbitofrontal cortical areas. In turn, the PAG has strong access to the caudal medullary nucleus retroambiguus (NRA). The NRA is the only cell group that has direct access to the motoneurons involved in vocalization, i.e., the motoneuronal cell groups innervating soft palate, pharynx, and larynx as well as diaphragm, intercostal, abdominal, and pelvic floor muscles. Together they determine the intraabdominal, intrathoracic, and subglottic pressure, control of which is necessary for generating vocalization. Only humans can speak, because, via the lateral component of the volitional or somatic motor system, they are able to modulate vocalization into words and sentences. For this modulation they use their motor cortex, which, via its corticobulbar fibers, has direct access to the motoneurons innervating the muscles of face, mouth, tongue, larynx, and pharynx. In conclusion, humans generate speech by activating two motor systems. They generate vocalization by activating the prefrontal-PAG-NRA-motoneuronal pathway, and, at the same time, they modulate this vocalization into words and sentences by activating the corticobulbar fibers to the face, mouth, tongue, larynx, and pharynx motoneurons. J. Comp. Neurol. 524:1558-1577, 2016. © 2015 Wiley Periodicals, Inc. PMID:26355872

  1. A Catalogue of Anatomical Fugitive Sheets: Cat. 11-25

    OpenAIRE

    1999-01-01

    Images Cat. 11 (a) Cat. 11 (b) Cat. 11 (c) Cat. 11 (d) Cat. 12: 1 (a) Cat. 12: 1 (b) Cat. 12: 2 (a) Cat. 12: 2 (b) Cat. 13 Cat. 14 (a) Cat. 14 (b) Cat. 14 (c) Cat. 15 (a) Cat. 15 (b) Cat. 17: 1 Cat. 17: 2 Cat. 18: 1 Cat. 18: 2 Cat. 19: 1 (a) Cat. 19: 1 (b) Cat. 19: 2 (a) Cat. 19: 2 (b) Cat. 20: 1 Cat. 20: 2 (a) Cat. 20: 2 (b) Cat. 21 (a) Cat. 21 (b) Cat. 21 (c) Cat. 21 (d) Cat. 21 (e) Cat. 22 Cat. 24: 1 and 2 Cat. 25: 1 Cat. 25: 2 Cat. 25: 3 Cat. 25: 4

  2. A tortoiseshell male cat

    DEFF Research Database (Denmark)

    Pedersen, A. S.; Berg, Lise Charlotte; Almstrup, Kristian;

    2014-01-01

    Tortoiseshell coat color is normally restricted to female cats due to X-linkage of the gene that encodes the orange coat color. Tortoiseshell male cats do, however, occur at a low frequency among tortoiseshell cats because of chromosome aberrations similar to the Klinefelter syndrome in man...... tissue from a tortoiseshell male cat referred to us. Chromosome analysis using RBA-banding consistently revealed a 39,XXY karyotype. Histological examinations of testis biopsies from this cat showed degeneration of the tubules, hyperplasia of the interstitial tissue, and complete loss of germ cells....... Immunostaining using anti-vimentin and anti-VASA (DDX4) showed that only Sertoli cells and no germ cells were observed in the testicular tubules. As no sign of spermatogenesis was detected, we conclude that this is a classic case of a sterile, male tortoiseshell cat with a 39,XXY chromosome complement. © 2013 S...

  3. That Fat Cat

    Science.gov (United States)

    Lambert, Phyllis Gilchrist

    2012-01-01

    This activity began with a picture book, Nurit Karlin's "Fat Cat On a Mat" (HarperCollins; 1998). The author and her students started their project with a 5-inch circular template for the head of their cats. They reviewed shapes as they drew the head and then added the ears and nose, which were triangles. Details to the face were added when…

  4. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System Winter Sports: Sledding, ... Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A ...

  5. Getting a CAT Scan

    Medline Plus

    Full Text Available ... Skiing, Snowboarding, Skating Crushes What's a Booger? Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A Text Size en español Obtención de ...

  6. Functional reorganization of sensorimotor cortex in early Parkinson disease.

    OpenAIRE

    Kojovic, M.; Bologna, M; Kassavetis, P.; Murase, N.; Palomar, F. J.; Berardelli, A; Rothwell, J C; Edwards, M. J.; Bhatia, K P

    2012-01-01

    OBJECTIVE: Compensatory reorganization of the nigrostriatal system is thought to delay the onset of symptoms in early Parkinson disease (PD). Here we sought evidence that compensation may be a part of a more widespread functional reorganization in sensorimotor networks, including primary motor cortex. METHODS: Several neurophysiologic measures known to be abnormal in the motor cortex (M1) of patients with advanced PD were tested on the more and less affected side of 16 newly diagnosed and dru...

  7. CAT questions and answers

    International Nuclear Information System (INIS)

    This document, prepared in February 1993, addresses the most common questions asked by APS Collaborative Access Teams (CATs). The answers represent the best judgment on the part of the APS at this time. In some cases, details are provided in separate documents to be supplied by the APS. Some of the answers are brief because details are not yet available. The questions are separated into five categories representing different aspects of CAT interactions with the APS: (1) Memorandum of Understanding (MOU), (2) CAT Beamline Review and Construction, (3) CAT Beamline Safety, (4) CAT Beamline Operations, and (5) Miscellaneous. The APS plans to generate similar documents as needed to both address new questions and clarify answers to present questions

  8. Postictal inhibition of the somatosensory cortex

    DEFF Research Database (Denmark)

    Beniczky, Sándor; Jovanovic, Marina; Atkins, Mary Doreen;

    2011-01-01

    Transient suppression of the motor cortex and of the speech areas cause well-described postictal phenomena following seizures involving the respective cortical areas. Pain is a rare symptom in epileptic seizures. We present a patient with painful tonic seizures in the left leg. The amplitude of t...

  9. Cortex commands the performance of skilled movement.

    Science.gov (United States)

    Guo, Jian-Zhong; Graves, Austin R; Guo, Wendy W; Zheng, Jihong; Lee, Allen; Rodríguez-González, Juan; Li, Nuo; Macklin, John J; Phillips, James W; Mensh, Brett D; Branson, Kristin; Hantman, Adam W

    2015-01-01

    Mammalian cerebral cortex is accepted as being critical for voluntary motor control, but what functions depend on cortex is still unclear. Here we used rapid, reversible optogenetic inhibition to test the role of cortex during a head-fixed task in which mice reach, grab, and eat a food pellet. Sudden cortical inhibition blocked initiation or froze execution of this skilled prehension behavior, but left untrained forelimb movements unaffected. Unexpectedly, kinematically normal prehension occurred immediately after cortical inhibition, even during rest periods lacking cue and pellet. This 'rebound' prehension was only evoked in trained and food-deprived animals, suggesting that a motivation-gated motor engram sufficient to evoke prehension is activated at inhibition's end. These results demonstrate the necessity and sufficiency of cortical activity for enacting a learned skill. PMID:26633811

  10. Orientation-tuned surround suppression in mouse visual cortex

    NARCIS (Netherlands)

    Self, Matthew W; Lorteije, Jeannette A M; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N; Heimel, J.A.; Roelfsema, Pieter R

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those contai

  11. StreamCat

    Data.gov (United States)

    U.S. Environmental Protection Agency — The StreamCat Dataset provides summaries of natural and anthropogenic landscape features for ~2.65 million streams, and their associated catchments, within the...

  12. Haemobartonellosis in Van Cats

    OpenAIRE

    AKKAN, Hasan Altan; Karaca, Mehmet; TÜTÜNCÜ, Mehmet

    2005-01-01

    The present study was conducted to determine prevalence of Haemobartonella felis in Van cats. 121 Van cats (82 female, 39 male, aged 1-9 years) were the materials of the study. To determine biochemical and haematological parameters, 2 ml blood with and without anticoagulant were taken according to technique from vena cephalica antebrachii. H. felis was detected in blood smears preparations of 18 (14.88%) by Papenheim staining. Among biochemical parameters aspartate amino transferase (AST), al...

  13. Resolving Schrodinger's cat

    OpenAIRE

    Hobson, Art

    2016-01-01

    Schrodinger's famous cat has long been misunderstood. According to quantum theory and experiments with entangled systems, an entangled state such as the Schrodinger's cat state is neither a superposition of states of either subsystem nor a superposition of compound states of the composite system, but rather a nonlocal superposition of correlations between pairs of states of the two subsystems. The entangled post-measurement state that results from an ideal measurement is not paradoxical, but ...

  14. Cardiac Biomarkers in Hyperthyroid Cats

    OpenAIRE

    Sangster, Jodi Kirsten

    2013-01-01

    Background: Hyperthyroidism has substantial effects on the circulatory system. The cardiac biomarkers NT-proBNP and troponin I (cTNI) have proven useful in identifying cats with myocardial disease but have not been as extensively investigated in hyperthyroidism.Hypothesis: Plasma NT-proBNP and cTNI concentrations are higher in cats with primary cardiac disease than in cats with hyperthyroidism and higher in cats with hyperthyroidism than in healthy control cats.Animals: Twenty-three hyperthyr...

  15. Cardiac Biomarkers in Hyperthyroid Cats

    OpenAIRE

    Sangster, J.K.; Panciera, D L; Abbott, J.A.; Zimmerman, K.C.; Lantis, A.C.

    2013-01-01

    Background Hyperthyroidism has substantial effects on the circulatory system. The cardiac biomarkers NT‐proBNP and troponin I (cTNI) have proven useful in identifying cats with myocardial disease but have not been extensively investigated in hyperthyroidism. Hypothesis Plasma NT‐proBNP and cTNI concentrations are higher in cats with primary myocardial disease than in cats with hyperthyroidism and higher in cats with hyperthyroidism than in healthy control cats. Animals Twenty‐three hyperthyro...

  16. Modularity of Endpoint Force Patterns Evoked Using Intraspinal Microstimulation in Treadmill Trained and/or Neurotrophin-Treated Chronic Spinal Cats

    OpenAIRE

    Boyce, Vanessa S.; Lemay, Michel A.

    2008-01-01

    Chronic spinal cats with neurotrophin-secreting fibroblasts (NTF) transplants recover locomotor function. To ascertain possible mechanisms, intraspinal microstimulation was used to examine the lumbar spinal cord motor output of four groups of chronic spinal cats: untrained cats with unmodified-fibroblasts graft (Op-control) or NTF graft and locomotor-trained cats with unmodified-fibroblasts graft (Trained) or NTF graft (Combination). Forces generated via intraspinal microstimulation at differ...

  17. E-Z-CAT

    International Nuclear Information System (INIS)

    A new barium sulphate suspension, E-Z-CAT, for use as an oral contrast medium at computed tomography of the abdomen has been compared with the commonly used water-soluble iodinated contrast medium Gastrografin as regards patient tolerance and diagnostic information. The investigation was conducted as an unpaired randomized single-blind study in 100 consecutive patients. E-Z-CAT seems to be preferred because of its better taste, its lesser tendency to cause diarrhoea, and for usage in patients who are known to be hypersensitive to iodinated contrast media. The diagnostic information was the same for both contrast media. (Auth.)

  18. Interference in motor learning - is motor interference sensory?

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye; Petersen, Tue Hvass; Rothwell, John C;

    Skill gained after a short period of practice in one motor task can be abolished if a second task is learned shortly afterwards, but not all motor activities cause interference. After all it is not necessary to remain completely still after practicing a task for learning to occur. Here we ask which...... mechanisms determine whether or not interference occurs. We hypothesised that interference requires the same neural circuits to be engaged in the two tasks and provoke competing processes of synaptic plasticity. To test this, subjects learned a ballistic ankle plantarflexion task. Early motor memory was...... learning of the primary task, no interference was observed. Previous studies have suggested that primary motor cortex (M1) may be involved in early motor memory consolidation. 1Hz Repetitive Transcranial Magnetic Stimulation (rTMS) of corticospinal motor output at intensities below ankle movement threshold...

  19. Motor deficits correlate with resting state motor network connectivity in patients with brain tumours

    OpenAIRE

    Otten, Marc L.; Mikell, Charles B; Youngerman, Brett E.; Liston, Conor; Sisti, Michael B.; Bruce, Jeffrey N.; Small, Scott A.; McKhann, Guy M.

    2012-01-01

    While a tumour in or abutting primary motor cortex leads to motor weakness, how tumours elsewhere in the frontal or parietal lobes affect functional connectivity in a weak patient is less clear. We hypothesized that diminished functional connectivity in a distributed network of motor centres would correlate with motor weakness in subjects with brain masses. Furthermore, we hypothesized that interhemispheric connections would be most vulnerable to subtle disruptions in functional connectivity....

  20. ServCat Sensitivity Guidelines

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This guide covers sensitivity in ServCat. This document provides technical guidance on how sensitivity fields work in ServCat, and provides suggestions on what...

  1. Reference values and clinical application of magnetic peripheral nerve stimulation in cats

    NARCIS (Netherlands)

    Van Soens, Iris; Struys, Michel M. R. F.; Bhatti, Sofie F. M.; Van Ham, Luc M. L.

    2012-01-01

    Magnetic stimulation of radial (RN) and sciatic (SN) nerves was performed bilaterally in 40 healthy cats. Reference values for onset latency and peak-to-peak amplitude of magnetic motor evoked potentials (MMEPs) were obtained and compared with values of electric motor evoked potentials (EMEPs) in 10

  2. Cat Scratch Disease (For Parents)

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth Cat Scratch Disease KidsHealth > For Parents > Cat Scratch Disease Print A A A Text Size ... Doctor en español Enfermedad por arañazo de gato Cat scratch disease is a bacterial infection that a ...

  3. Tracheal collapse in two cats

    International Nuclear Information System (INIS)

    Two cats examined bronchoscopically to discover the cause of tracheal collapse were found to have tracheal obstruction cranial to the collapse. Cats with this unusual sign should be examined bronchoscopically to ascertain whether there is an obstruction, as the cause in these 2 cats was distinct from the diffuse airway abnormality that causes tracheal collapse in dogs

  4. Membranous nephropathy in sibling cats.

    Science.gov (United States)

    Nash, A S; Wright, N G

    1983-08-20

    Membranous nephropathy was diagnosed in two sibling cats from the same household. Both cases presented with the nephrotic syndrome but 33 months elapsed before the second cat became ill, by which time the first cat had been in full clinical remission for over a year. PMID:6623883

  5. Taxonomy Icon Data: domestic cat [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available domestic cat ... Felis silvestris cat us Chordata/Vertebrata/Mammalia/Theria/Eutheria/Carnivora Felis ... _silvestris_cat us_L.png Felis_silvestris_cat us_NL.png Felis_silves ... tris_cat us_S.png Felis_silvestris_cat us_NS.png http://biosc ...

  6. Getting a CAT Scan

    Medline Plus

    Full Text Available ... More Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading Back-to-School ... Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands ...

  7. Chemodectoma in a cat

    International Nuclear Information System (INIS)

    A 10-year-old, spayed female, domestic shorthair cat was presented for evaluation of a thoracic mass. Radiographs demonstrated a 4 by 5-cm mass dorsal to the heart. Cytology of specimens obtained by ultrasound-guided needle aspiration was compatible with a neuroendocrine tumor. Scintigraphy, thoracic exploratory, and histology were used to identify the mass as an aortic body chemodectoma

  8. Coxofemoral luxations in cats

    International Nuclear Information System (INIS)

    In a retrospective study, 79 untreated luxations of the coxofemoral joint in cats were recorded over a 12-year period. Twenty-nine of these cases were available for follow-up, of which 13 were re-examined clinically and radiologically. It was found that the maximum incidence of the injury occurred from one to three years of age. Follow-up radiographs showed that the cats had developed nearthroses of various degrees located dorsally on the ilium. The degree of nearthrosis formation was not consistently correlated with the length of the observation time. Radiological signs of decreased bone density of the proximal femur may be caused by reduced weightbearing related to changes in biomechanical function and altered blood supply in the luxated limb. Almost two-thirds of the re-examined animals presented some kind of locomotor dysfunction on clinical examination. Limb function improved with time. The best clinical results appeared to be in cats that were immature at the time of injury and developed nearthrosis similar to a normal coxofemoral joint. All the cats available to this study showed acceptable functional results and had a normal level of activity according to the owners

  9. Getting a CAT Scan

    Medline Plus

    Full Text Available ... More Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System ... Video) Print A A A Text Size en español Obtención de una tomografía computada (video) CAT stands ...

  10. The Fishing Cat

    Institute of Scientific and Technical Information of China (English)

    孙雅飞; 乐伟国

    2008-01-01

    @@ 一、故事内容 A cat goes fishing every day. He wants to eat fish, but he can't catch any fish. One day, he goes to the river as usual. Suddenly, a fish comes out. He catches the fish and putsthe fish in the basket. He's very happy, but he forgest to put the lid on the basket.

  11. Oligopsonistic Cats and Dogs

    OpenAIRE

    Dewit, Dr. Gerda; Leahy, Dr. Dermot

    2005-01-01

    We study the strategic investment behaviour of oligopsonistic rivals in the labour market. Under wage competition, firms play "puppy dog" with productivityaugmenting investment and "fat cat" with supply-enhancing investment. Under employment competition, investing strategically always involves playing "top dog".

  12. Developing Neocortex Organization and Connectivity in Cats Revealed by Direct Correlation of Diffusion Tractography and Histology

    OpenAIRE

    Takahashi, Emi; Dai, Guangping; Glenn D. Rosen; Wang, Ruopeng; Ohki, Kenichi; Rebecca D. Folkerth; Galaburda, Albert M.; Wedeen, Van J.; P. Ellen Grant

    2010-01-01

    The immature cortex (cortical plate [CP]) and underlying subplate (SP), a transient cell layer just below the CP, play critical roles in the formation of intracerebral connections. The purpose of this study was to examine the diffusion characteristics of the developing cortex and subcortical structures and compare to histology. We obtained high-resolution diffusion spectrum images of postnatal day (P) 0 (newborn), P35 (pediatric), and P100 (adult) cat brains, performed tractography analysis, ...

  13. The insular cortex: a comparative perspective.

    Science.gov (United States)

    Butti, Camilla; Hof, Patrick R

    2010-06-01

    The human insular cortex is involved in a variety of viscerosensory, visceromotor, and interoceptive functions, and plays a role in complex processes such as emotions, music, and language. Across mammals, the insula has considerable morphologic variability. We review the structure and connectivity of the insula in laboratory animals (mouse, domestic cat, macaque monkey), and we present original data on the morphology and cytoarchitecture of insular cortex in less common species including a large carnivore (the Atlantic walrus, Odobenus rosmarus), two artiodactyls (the pigmy hippopotamus, Hexaprotodon liberiensis, and the Western bongo, Tragelaphus eurycerus), two cetaceans (the beluga whale, Delphinapterus leucas, and the minke whale, Balaenoptera acutorostrata), and a sirenian (the Florida manatee, Trichechus manatus latirostris). The insula shows substantial variability in shape, extent, and gyral and sulcal patterns, as well as differences in laminar organization, cellular specialization, and structural association with the claustrum. Our observations reveal that the insular cortex is extremely variable among mammals. These differences could be related to the role exerted by specific and selective pressures on cortical structure during evolution. We conclude that it is not possible to identify a general model of organization for the mammalian insular cortex. PMID:20512368

  14. Enhanced Motor Learning Following Task-Concurrent Dual Transcranial Direct Current Stimulation

    OpenAIRE

    Karok, Sophia; Witney, Alice G.

    2013-01-01

    Objective Transcranial direct current stimulation (tDCS) of the primary motor cortex (M1) has beneficial effects on motor performance and motor learning in healthy subjects and is emerging as a promising tool for motor neurorehabilitation. Applying tDCS concurrently with a motor task has recently been found to be more effective than applying stimulation before the motor task. This study extends this finding to examine whether such task-concurrent stimulation further enhances motor learning on...

  15. Prostatic carcinoma in two cats

    International Nuclear Information System (INIS)

    Clinical, radiological and pathological features of two cats with prostatic carcinoma are reported. In both cats the presenting history included signs of lower urinary tract disease with haematuria and dysuria. Prostatomegaly was visible radiographically in one cat; an irregular intraprostatic urethra was seen on retrograde contrast urethrography in both cats. In one of the cats, neoplasia was suspected on the basis of a transurethral catheter biopsy. Following a poor response to palliative treatment in both cases, euthanasia was performed with histological confirmation of the diagnosis

  16. The Cat nRules

    CERN Document Server

    Mould, R A

    2004-01-01

    The nRules that are developed in another paper are applied to two versions of the Schrodinger cat experiment. In version I the initially conscious cat is made unconscious by a mechanism that is initiated by a radioactive decay. In version II the initially unconscious cat is awakened by a mechanism that is initiated by a radioactive decay. In both cases an observer is permitted to check the statues of the cat at any time during the experiment. In all cases the nRules correctly and unambiguously predict the conscious experience of the cat and the observer. Keywords: brain states of observer, stochastic choice, state reduction, wave collapse.

  17. Motor cortical plasticity induced by motor learning through mental practice.

    Directory of Open Access Journals (Sweden)

    Nicolas Gueugneau

    2015-04-01

    Full Text Available Several investigations suggest that actual and mental actions trigger similar neural substrates. Motor learning via physical practice results in long-term potentiation (LTP-like plasticity processes, namely potentiation of M1 and a temporary occlusion of additional LTP-like plasticity. However, whether this neuroplasticity process contributes to improve motor performance through mental practice remains to be determined. Here, we tested skill learning-dependent changes in primary motor cortex (M1 excitability and plasticity by means of transcranial magnetic stimulation in subjects trained to physically execute or mentally perform a sequence of finger opposition movements. Before and after physical practice and motor-imagery practice, M1 excitability was evaluated by measuring the input-output (IO curve of motor evoked potentials. M1 long-term potentiation (LTP and long-term depression (LTD-like plasticity was assessed with paired-associative stimulation (PAS of the median nerve and motor cortex using an interstimulus interval of 25 ms (PAS25 or 10 ms (PAS10, respectively. We found that even if after both practice sessions subjects significantly improved their movement speed, M1 excitability and plasticity were differentially influenced by the two practice sessions. First, we observed an increase in the slope of IO curve after physical but not after motor-imagery practice. Second, there was a reversal of the PAS25 effect from LTP-like plasticity to LTD-like plasticity following physical and motor-imagery practice. Third, LTD-like plasticity (PAS10 protocol increased after physical practice, whilst it was occluded after motor-imagery practice. In conclusion, we demonstrated that motor-imagery practice lead to the development of neuroplasticity, as it affected the PAS25- and PAS10- induced plasticity in M1. These results, expanding the current knowledge on how motor-imagery training shapes M1 plasticity, might have a potential impact in

  18. Genetic testing in domestic cats.

    Science.gov (United States)

    Lyons, Leslie A

    2012-12-01

    Varieties of genetic tests are currently available for the domestic cat that support veterinary health care, breed management, species identification, and forensic investigations. Approximately thirty-five genes contain over fifty mutations that cause feline health problems or alterations in the cat's appearance. Specific genes, such as sweet and drug receptors, have been knocked-out of Felidae during evolution and can be used along with mtDNA markers for species identification. Both STR and SNP panels differentiate cat race, breed, and individual identity, as well as gender-specific markers to determine sex of an individual. Cat genetic tests are common offerings for commercial laboratories, allowing both the veterinary clinician and the private owner to obtain DNA test results. This article will review the genetic tests for the domestic cat, and their various applications in different fields of science. Highlighted are genetic tests specific to the individual cat, which are a part of the cat's genome. PMID:22546621

  19. Stimulation of motor tracts in multiple sclerosis.

    OpenAIRE

    Berardelli, A; Inghilleri, M; Cruccu, G.; Fornarelli, M; Accornero, N; Manfredi, M.

    1988-01-01

    Percutaneous electrical stimulation of the motor cortex was used to evaluate corticospinal conduction to upper-limb motoneurons in 29 patients with multiple sclerosis. Central motor conduction abnormalities were correlated with clinical signs and somatosensory evoked potentials. Muscle responses to cortical stimulation were altered in 20 patients. The most common abnormality was increased central motor conduction time; in two cases the responses to cortical stimulation were absent. Abnormalit...

  20. Motor activation in SPG4-linked hereditary spastic paraplegia

    DEFF Research Database (Denmark)

    Scheuer, KH; Nielsen, JE; Krabbe, Katja;

    2006-01-01

    , the supplementary motor areas and the right premotor cortex compared to controls. CONCLUSIONS: Motor cortical reorganisation may explain this result, but as no significant differences were recognised in the motor response of the unaffected limb, differences in functional demands should also be...

  1. The cat is out of the bag

    KAUST Repository

    Ananthanarayanan, Rajagopal

    2009-01-01

    In the quest for cognitive computing, we have built a massively parallel cortical simulator, C2, that incorporates a number of innovations in computation, memory, and communication. Using C2 on LLNL\\'s Dawn Blue Gene/P supercomputer with 147, 456 CPUs and 144 TB of main memory, we report two cortical simulations - at unprecedented scale - that effectively saturate the entire memory capacity and refresh it at least every simulated second. The first simulation consists of 1.6 billion neurons and 8.87 trillion synapses with experimentally-measured gray matter thalamocortical connectivity. The second simulation has 900 million neurons and 9 trillion synapses with probabilistic connectivity. We demonstrate nearly perfect weak scaling and attractive strong scaling. The simulations, which incorporate phenomenological spiking neurons, individual learning synapses, axonal delays, and dynamic synaptic channels, exceed the scale of the cat cortex, marking the dawn of a new era in the scale of cortical simulations. Copyright 2009 ACM.

  2. The Cheshire Cat revisited

    CERN Document Server

    Vento, V

    1998-01-01

    The concept of effective field theory leads in a natural way to a construction principle for phenomenological sensible models known under the name of the Cheshire Cat Principle. We review its formulation in the chiral bag scenario and discuss its realization for the flavor singlet axial charge. Quantum effects inside the chiral bag induce a color anomaly which requires a compensating surface term to prevent breakdown of color gauge invariance. The presence of this surface term allows one to derive in a gauge-invariant way a chiral-bag version of the Shore-Veneziano two-component formula for the flavor-singlet axial charge of the proton. We show that one can obtain a striking Cheshire-Cat phenomenon with a negligibly small singlet axial charge.

  3. 大脑半球切除术后患者上肢运动功能定位及神经功能重塑性研究%Upper limbs motor maps in cortex and plasticity after the anatomical hemispherectomy

    Institute of Scientific and Technical Information of China (English)

    刘源; 曲金荣; 李少武; 徐宇伦

    2009-01-01

    Objective To locate motor functional area of patients who underwent modified anatomical hemisphereetomy in order to analyze the plasticity of upper limbs motor. Methods From July to December 2007 the patients who underwent modified anatomical hemispherectomy were performed BOLD sequences,to locate functional cortical areas in their residual brain. Results Six patients had performed examination of BOLl) sequences by 3.0-T MRI. Five of them obtained cuntralateral upper limb motor areas in their residual brain ,and 3 of them obtained ipsilateral and contralateral upper limb motor area map in cortex. The ipsilateral upper limb motor areas in the M1, SMA and posterior parietal cortex. Conclusions The patients who underwent modified anatomical hemispherectomy is an excellent model to investigate mechanism of plasticity in the developing brain. Functional magnetic resonance (fMRI) providing fine spatial detail of brain responses, would describle the motor functional area of cortical maps. These patients exist ipsilater motor areas in their residual monohemisphere. The study indicates that there maybe somewhat extent of correlation between the surgerical procedure and the outcome of neuroplasticity.%目的 对改良式大脑半球切除术后患者进行肢体运动在同侧大脑半球的功能定位及其神经功能重塑的研究.方法 2007年7月至12月以改良式解剖性大脑半球切除术后患者为研究对象,使用3.0 T磁共振仪行大脑运动功能磁共振(fMRI)检测.受检者分别行双侧上肢屈肘运动,使用BOLD序列,检测双侧上肢运动在健侧大脑半球的皮质投射区.结果 6例行改良式解剖性大脑半球切除术后患者有5例检测出对侧肢体运动fMRI代表区,其中3例得到双侧上肢在健侧大腑皮质的运动代表区.同侧上肢运动定位区出现在第一运动区、辅助运动区和顶后小叶皮质.结论 在人类一侧大脑半球切除后,健侧大脑半球存在支配同侧肢体运动的功

  4. Sensory experience modifies feature map relationships in visual cortex.

    Science.gov (United States)

    Cloherty, Shaun L; Hughes, Nicholas J; Hietanen, Markus A; Bhagavatula, Partha S; Goodhill, Geoffrey J; Ibbotson, Michael R

    2016-01-01

    The extent to which brain structure is influenced by sensory input during development is a critical but controversial question. A paradigmatic system for studying this is the mammalian visual cortex. Maps of orientation preference (OP) and ocular dominance (OD) in the primary visual cortex of ferrets, cats and monkeys can be individually changed by altered visual input. However, the spatial relationship between OP and OD maps has appeared immutable. Using a computational model we predicted that biasing the visual input to orthogonal orientation in the two eyes should cause a shift of OP pinwheels towards the border of OD columns. We then confirmed this prediction by rearing cats wearing orthogonally oriented cylindrical lenses over each eye. Thus, the spatial relationship between OP and OD maps can be modified by visual experience, revealing a previously unknown degree of brain plasticity in response to sensory input. PMID:27310531

  5. Sensory experience modifies feature map relationships in visual cortex

    Science.gov (United States)

    Cloherty, Shaun L; Hughes, Nicholas J; Hietanen, Markus A; Bhagavatula, Partha S

    2016-01-01

    The extent to which brain structure is influenced by sensory input during development is a critical but controversial question. A paradigmatic system for studying this is the mammalian visual cortex. Maps of orientation preference (OP) and ocular dominance (OD) in the primary visual cortex of ferrets, cats and monkeys can be individually changed by altered visual input. However, the spatial relationship between OP and OD maps has appeared immutable. Using a computational model we predicted that biasing the visual input to orthogonal orientation in the two eyes should cause a shift of OP pinwheels towards the border of OD columns. We then confirmed this prediction by rearing cats wearing orthogonally oriented cylindrical lenses over each eye. Thus, the spatial relationship between OP and OD maps can be modified by visual experience, revealing a previously unknown degree of brain plasticity in response to sensory input. DOI: http://dx.doi.org/10.7554/eLife.13911.001 PMID:27310531

  6. Responses of primate frontal cortex neurons during natural vocal communication.

    Science.gov (United States)

    Miller, Cory T; Thomas, A Wren; Nummela, Samuel U; de la Mothe, Lisa A

    2015-08-01

    The role of primate frontal cortex in vocal communication and its significance in language evolution have a controversial history. While evidence indicates that vocalization processing occurs in ventrolateral prefrontal cortex neurons, vocal-motor activity has been conjectured to be primarily subcortical and suggestive of a distinctly different neural architecture from humans. Direct evidence of neural activity during natural vocal communication is limited, as previous studies were performed in chair-restrained animals. Here we recorded the activity of single neurons across multiple regions of prefrontal and premotor cortex while freely moving marmosets engaged in a natural vocal behavior known as antiphonal calling. Our aim was to test whether neurons in marmoset frontal cortex exhibited responses during vocal-signal processing and/or vocal-motor production in the context of active, natural communication. We observed motor-related changes in single neuron activity during vocal production, but relatively weak sensory responses for vocalization processing during this natural behavior. Vocal-motor responses occurred both prior to and during call production and were typically coupled to the timing of each vocalization pulse. Despite the relatively weak sensory responses a population classifier was able to distinguish between neural activity that occurred during presentations of vocalization stimuli that elicited an antiphonal response and those that did not. These findings are suggestive of the role that nonhuman primate frontal cortex neurons play in natural communication and provide an important foundation for more explicit tests of the functional contributions of these neocortical areas during vocal behaviors. PMID:26084912

  7. Orientation-tuned surround suppression in mouse visual cortex

    OpenAIRE

    Self, Matthew W.; Lorteije, Jeannette A. M.; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N.; Heimel, J.A.; Roelfsema, Pieter R.

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those containing orientation contrast. This effect is thought to be important for scene segmentation, but the underlying neural mechanisms are poorly understood. We asked whether it is possible to study these ...

  8. Adaptive filtering enhances information transmission in visual cortex

    OpenAIRE

    Sharpee, Tatyana O.; Sugihara, Hiroki; Kurgansky, Andrei V.; Rebrik, Sergei P.; Stryker, Michael P.; Miller, Kenneth D.

    2006-01-01

    Sensory neuroscience seeks to understand how the brain encodes natural environments. However, neural coding has largely been studied using simplified stimuli. In order to assess whether the brain’s coding strategy depends on the stimulus ensemble, we apply a new information-theoretic method that allows unbiased calculation of neural filters (receptive fields) from responses to natural scenes or other complex signals with strong multipoint correlations. In the cat primary visual cortex we comp...

  9. Local cloning of CAT states

    International Nuclear Information System (INIS)

    In this Letter we analyze the (im)possibility of the exact cloning of orthogonal three-qubit CAT states under local operation and classical communication (LOCC) with the help of a restricted entangled state. We also classify the three-qubit CAT states that can (not) be cloned under LOCC restrictions and extend the results to the n-qubit case. -- Highlights: → We analyze the (im)possibility of exact cloning of orthogonal CAT states under LOCC. → We also classify the set of CAT states that can(not) be cloned by LOCC. → No set of orthogonal CAT states can be cloned by LOCC with help of similar CAT state. → Any two orthogonal n-qubit GHZ-states can be cloned by LOCC with help of a GHZ state.

  10. Environmental Enrichment for Indoor Cats

    OpenAIRE

    Herron, Meghan E.; Buffington, C. A. Tony

    2010-01-01

    Recommendations to cat owners to house their cats indoors confer the responsibility to provide conditions that ensure good health and welfare. Cats maintain their natural behaviors, such as scratching, chewing, and elimination, while living indoors, and they may develop health and behavior problems when deprived of appropriate environmental outlets for these behaviors. This article divides the environment into five basic “systems” to enable identification of features that may benefit from imp...

  11. Hypereosinophilic syndrome in two cats.

    Science.gov (United States)

    Takeuchi, Yoshinori; Matsuura, Shinobu; Fujino, Yasuhito; Nakajima, Mayumi; Takahashi, Masashi; Nakashima, Ko; Sakai, Yusuke; Uetsuka, Koji; Ohno, Koichi; Nakayama, Hiroyuki; Tsujimoto, Hajime

    2008-10-01

    Two cats showing chronic vomiting, diarrhea and weight loss were found to have leukocytosis with marked eosinophilia. Both cats were diagnosed with hypereosinophilic syndrome by the findings of increased eosinophils and their precursors in the bone marrow, eosinophilic infiltration into multiple organs, and exclusion of other causes for eosinophilia. Although cytoreductive chemotherapy with hydroxycarbamide and prednisolone was performed, these two cats died 48 days and 91 days after the initial presentation. PMID:18981665

  12. Environmental enrichment for indoor cats.

    Science.gov (United States)

    Herron, Meghan E; Buffington, C A Tony

    2010-12-01

    Recommendations to cat owners to house their cats indoors confer the responsibility to provide conditions that ensure good health and welfare. Cats maintain their natural behaviors, such as scratching, chewing, and elimination, while living indoors, and they may develop health and behavior problems when deprived of appropriate environmental outlets for these behaviors. This article divides the environment into five basic "systems" to enable identification of features that may benefit from improvement. It also addresses practical means of meeting cats' needs in each of these systems. PMID:21882164

  13. The Cat nRules

    OpenAIRE

    Mould, Richard A

    2004-01-01

    The nRules that are developed in another paper are applied to two versions of the Schrodinger cat experiment. In version I the initially conscious cat is made unconscious by a mechanism that is initiated by a radioactive decay. In version II the initially unconscious cat is awakened by a mechanism that is initiated by a radioactive decay. In both cases an observer is permitted to check the statues of the cat at any time during the experiment. In all cases the nRules correctly and unambiguousl...

  14. cats and dogs

    Institute of Scientific and Technical Information of China (English)

    颜玉秀

    2003-01-01

    有这样一则英语成语:“To rain cats anddogs.”如果望文生义,则会被译为“下猫下狗”,因而会弄出许多笑话来,这应当是值得引以为戒的。其实这句成语的真正含义是:“下倾盆大雨”。那么下雨为什么会与cats和dogs联系在一起呢?

  15. EzCatDB: M00143 [EzCatDB

    Lifescience Database Archive (English)

    Full Text Available http://ezcatdb.cbrc.jp/EzCatDB/search/get.do?dbcode=M00143 EzCatDB M00143 0) { response = "?" + ... 1995 Volume 34 Pages 955-64 Authors Mimeault M, De Lean ... A, Lafleur M, Bonenfant D, Fournier A Title Evalua ...

  16. Effects of lumbosacral epidural ketamine and lidocaine inxylazine-sedated cats : article

    OpenAIRE

    R. DeRossi; A.P. Benites; J.Z. Ferreira; J.M.N. Neto; L.C. Hermeto

    2009-01-01

    In order to determine the analgesic and cardiovascular effects of the combination of epidural ketamine and lidocaine, 6 sedated cats were studied. Six healthy, young cats were used in a prospective randomised study. Each cat underwent 3 treatments, at least 1 week apart, via epidural injection: (1) ketamine (2.5 mg/kg), (2) lidocaine (4.0 mg/kg), and (3) ketamine (2.5 mg/kg) plus lidocaine (4.0 mg/kg). Epidural injections were administered through the lumbosacral space. Analgesia, motor block...

  17. Toxoplasmosis: An Important Message for Cat Owners

    Science.gov (United States)

    ... role do cats play in the spread of toxoplasmosis? Cats get Toxoplasma infection by eating infected rodents, ... an infected cat may have defecated. What is toxoplasmosis? Toxoplasmosis is an infection caused by a microscopic ...

  18. How transcranial direct current stimulation can modulate implicit motor sequence learning and consolidation: A brief review

    Directory of Open Access Journals (Sweden)

    Branislav eSavic

    2016-02-01

    Full Text Available The purpose of this review is to investigate how transcranial direct current stimulation (tDCS can modulate implicit motor sequence learning and consolidation. So far, most of the studies have focused on the modulating effect of tDCS for explicit motor learning. Here, we focus explicitly on implicit motor sequence learning and consolidation in order to improve our understanding about the potential of tDCS to affect this kind of unconscious learning. Specifically, we concentrate on studies with the serial reaction time task (SRTT, the classical paradigm for measuring implicit motor sequence learning. The influence of tDCS has been investigated for the primary motor cortex, the premotor cortex, the prefrontal cortex, and the cerebellum. The results indicate that tDCS above the primary motor cortex gives raise to the most consistent modulating effects for both implicit motor sequence learning and consolidation.

  19. How Transcranial Direct Current Stimulation Can Modulate Implicit Motor Sequence Learning and Consolidation: A Brief Review.

    Science.gov (United States)

    Savic, Branislav; Meier, Beat

    2016-01-01

    The purpose of this review is to investigate how transcranial direct current stimulation (tDCS) can modulate implicit motor sequence learning and consolidation. So far, most of the studies have focused on the modulating effect of tDCS for explicit motor learning. Here, we focus explicitly on implicit motor sequence learning and consolidation in order to improve our understanding about the potential of tDCS to affect this kind of unconscious learning. Specifically, we concentrate on studies with the serial reaction time task (SRTT), the classical paradigm for measuring implicit motor sequence learning. The influence of tDCS has been investigated for the primary motor cortex, the premotor cortex, the prefrontal cortex, and the cerebellum. The results indicate that tDCS above the primary motor cortex gives raise to the most consistent modulating effects for both implicit motor sequence learning and consolidation. PMID:26903837

  20. Accelerator programme at CAT

    International Nuclear Information System (INIS)

    The Accelerator Programme at the Centre for Advanced Technology (CAT), Indore, has very broad based concept under which all types of accelerators are to be taken up for design and fabrication. This centre will be housing a wide variety of accelerators to serve as a common facility for the universities, national laboratories in addition to laboratories under the Department of Atomic Energy. In the first phase of the programme, a series of electron accelerators are designed and fabricated. They are synchrotron radiation sources of 450 MeV (INDUS-I) and of 2 GeV (INDUS-II), microtron upto energy of 20 MeV, linear accelerator upto 20 MeV, and DC Accelerator for industrial irradiation upto 750 KeV and 20 KW. A proton accelerator of 300 MeV with 20 MeV linac injector is also designed. CAT is also developing a strong base for support technologies like ultra high vacuum, radio frequency and microwaves, DC pulsed and superconducting magnets, power supplies and controls etc. These technologies are very useful for other industrial applications also. To develop user groups to utilise INDUS-II synchrotron radiation source, a batch production of rotating Anode X-ray generators with power supplies has been initiated. So also, the sputter ion pumps, electron guns, turbo molecular pumps are brought into batch production. (author)

  1. CONTRACT ADMINISTRATIVE TRACKING SYSTEM (CATS)

    Science.gov (United States)

    The Contract Administrative Tracking System (CATS) was developed in response to an ORD NHEERL, Mid-Continent Ecology Division (MED)-recognized need for an automated tracking and retrieval system for Cost Reimbursable Level of Effort (CR/LOE) Contracts. CATS is an Oracle-based app...

  2. College Students and Their Cats

    Science.gov (United States)

    Weinstein, Lawrence; Alexander, Ralph

    2010-01-01

    Twenty-two Siamese and 32 mixed breed cats' personalities were rated by their respective college student owners and compared. Further, the owners' self rated personality traits were correlated with the pets'; significant Siamese and Mixed differences and correlations were obtained. These are the first data to examine breed of cat on a personality…

  3. [Glomerulonephritis in dogs and cats].

    Science.gov (United States)

    Reinacher, M; Frese, K

    1991-04-01

    Immunohistology and special staining of plastic sections allow diagnosis and differentiation of subtypes of glomerulonephritis in dogs. Frequency and clinical importance of these forms of glomerulonephritis vary significantly. In cats, glomerulonephritis occurs frequently in FIV-positive cats but is rare in animals suffering from persistent FeLV infection or FIP. PMID:2068715

  4. Peritoneopericardial diaphragmatic hernia in cats

    International Nuclear Information System (INIS)

    Peritoneopericardial diaphragmatic hernia in a cat is often an incidental finding on a routine thoracic or abdominal radiograph. Clinical signs are nonspecific-usually respiratory (dyspnea) or gastrointestinal(vomiting or diarrhea). Some of the cats with this anomaly are asymptomatic. The physical examination may be normal: muffled heart sounds are the most common abnormality noted during a physical examination. Cats of many breeds are affected, although 26% of reported cases were inPersians. Age of the cat at diagnosis ranged from 6 days to 14 years. Thirty of the 52 reported cases were in females. Diagnostic studies used to confirm the diagnosis included echocardiography, upper gastrointestinal study, ultrasonography, angiography, positive-contrast peritoneography, and laparotomy. Surgical correction was reportedly successful in 22 of 25 cats

  5. A Mediating Role of the Premotor Cortex in Phoneme Segmentation

    Science.gov (United States)

    Sato, Marc; Tremblay, Pascale; Gracco, Vincent L.

    2009-01-01

    Consistent with a functional role of the motor system in speech perception, disturbing the activity of the left ventral premotor cortex by means of repetitive transcranial magnetic stimulation (rTMS) has been shown to impair auditory identification of syllables that were masked with white noise. However, whether this region is crucial for speech…

  6. Instructive signals for motor learning from visual cortical area MT

    OpenAIRE

    Carey, Megan R; Medina, Javier F.; Lisberger, Stephen G.

    2005-01-01

    Sensory error signals have long been proposed to act as instructive signals to guide motor learning. Here we have exploited the temporal specificity of learning in smooth pursuit eye movements and the well-defined anatomical structure of the neural circuit for pursuit to identify a part of sensory cortex that provides instructive signals for motor learning in monkeys. We show that electrical microstimulation in the motion-sensitive middle temporal area (MT) of extrastriate visual cortex instr...

  7. Response properties of cat AMLS neurons to optic flow stimuli

    Institute of Scientific and Technical Information of China (English)

    LI; Baowang(李宝旺); LI; Bing(李兵); CHEN; Hui(陈辉); XU; Ying(徐颖); DIAO; Yuncheng(刁云程)

    2002-01-01

    Spiral and translation stimuli were used to investigate the response properties of cat AMLS (anteromedial lateral suprasylvian area) neurons to optic flow. The overwhelming majority of cells could be significantly excited by the two modes of stimuli and most responsive cells displayed obvious direction selectivity. It is the first time to find a visual area in mammalian brain preferring rotation stimuli. Two representative hypotheses are discussed here on the neural mechanism of optic flow analysis in visual cortex, and some new viewpoints are proposed to explain the experimental results.

  8. Like herding cats.

    Science.gov (United States)

    Muller-Smith, P

    1997-12-01

    In an effort to be a good manager, it is easy to lose sight of the fact that knowledge workers require a unique approach from their manager. Because nurses are independent and capable individuals that prosper in an environment that recognizes them as knowledge workers, nurse managers often find that traditional management techniques are not sufficient. Trying to manage all of the nurses on a unit as a single group is much like trying to herd cats. It might be less frustrating for the nurse manager to lead gently rather than manage with a firm hand. Warren Bennis suggests that this approach may provide a valuable key to successfully managing in a world of constant change. PMID:9464034

  9. Cat Ownership Perception and Caretaking Explored in an Internet Survey of People Associated with Cats

    OpenAIRE

    Zito, Sarah; Vankan, Dianne; Bennett, Pauleen; Paterson, Mandy; Phillips, Clive J. C.

    2015-01-01

    People who feed cats that they do not perceive they own (sometimes called semi-owners) are thought to make a considerable contribution to unwanted cat numbers because the cats they support are generally not sterilized. Understanding people’s perception of cat ownership and the psychology underlying cat semi-ownership could inform approaches to mitigate the negative effects of cat semi-ownership. The primary aims of this study were to investigate cat ownership perception and to examine its ass...

  10. Biomolecular motors

    Directory of Open Access Journals (Sweden)

    Henry Hess

    2005-12-01

    Here, we give a brief introduction to molecular motors, with an emphasis on motor proteins, describe the challenges in interfacing these bionanomachines with an artificial environment, and provide examples of emerging applications.

  11. Motor cortical regulation of sparse synergies provides a framework for the flexible control of precision walking

    Directory of Open Access Journals (Sweden)

    Trevor Drew

    2013-07-01

    Full Text Available We have previously described a modular organisation of the locomotor step cycle in the cat in which a number of sparse synergies are activated sequentially during the swing phase of the step cycle (Krouchev et al. 2006. Here, we address how these synergies are modified during voluntary gait modifications. Data were analysed from 27 bursts of muscle activity (recorded from18 muscles recorded in the forelimb of the cat during locomotion. These were grouped into 10 clusters, or synergies, during unobstructed locomotion. Each synergy was comprised of only a small number of muscles bursts (sparse synergies, some of which included both proximal and distal muscles. Eight (8/10 of these synergies were active during the swing phase of locomotion. Synergies observed during the gait modifications were very similar to those observed during unobstructed locomotion. Constraining these synergies to be identical in both the lead (first forelimb to pass over the obstacle and the trail (second limb conditions allowed us to compare the changes in phase and magnitude of the synergies required to modify gait. In the lead condition, changes were observed particularly in those synergies responsible for transport of the limb and preparation for landing. During the trail condition, changes were particularly evident in those synergies responsible for lifting the limb from the ground at the onset of the swing phase. These changes in phase and magnitude were adapted to the size and shape of the obstacle over which the cat stepped. These results demonstrate that by modifying the phase and magnitude of a finite number of muscle synergies, each comprised of a small number of simultaneously active muscles, descending control signals could produce very specific modifications in limb trajectory during locomotion. We discuss the possibility that these changes in phase and magnitude could be produced by changes in the activity of neurones in the motor cortex.

  12. Functional Neuroimaging of Motor Control inParkinson’s Disease

    DEFF Research Database (Denmark)

    Herz, Damian M; Eickhoff, Simon B; Løkkegaard, Annemette;

    2014-01-01

    denervation affects neural processing in the denervated striatal motor territory. In contrast, fronto-parietal motor areas display both increases as well as decreases in movement related activation. This points to a more complex relationship between altered cortical physiology and nigrostriatal dopaminergic...... and yielded consistent alterations in neural activity in patients with PD. Differences in cortical activation between PD patients and healthy controls converged in a left-lateralized fronto-parietal network comprising the presupplementary motor area, primary motor cortex, inferior parietal cortex, and...... posterior motor putamen, which improved with dopaminergic medication. The likelihood of detecting a decrease in putaminal activity increased with motor impairment. This reduced motor activation of the posterior putamen across previous neuroimaging studies indicates that nigrostriatal dopaminergic...

  13. Short colon in a cat

    International Nuclear Information System (INIS)

    An 11-year-old male Japanese domestic cat was referred to the veterinary hospital with a chronic diarrhea and signs of pain and vocalization when defecating. The cat has discharged unformed feces throughout his life. Morphological diagnosis of short colon was made radiographically after barium enema. The ileocolic junction and cecum was located to the left of the midline at the proximal end of the descending colon. Additional endoscopic examination demonstrated the difference in visual structures of the mucosal surface and in histological structures on mucosal biopsy specimens, between the colon and ileum. This is the first report of short colon in a cat in Japan

  14. TMS-Induced Modulation of Action Sentence Priming in the Ventral Premotor Cortex

    Science.gov (United States)

    Tremblay, Pascale; Sato, Marc; Small, Steven L.

    2012-01-01

    Despite accumulating evidence that cortical motor areas, particularly the lateral premotor cortex, are activated during language comprehension, the question of whether motor processes help mediate the semantic encoding of language remains controversial. To address this issue, we examined whether low frequency (1 Hz) repetitive transcranial…

  15. Apraxia and motor dysfunction in corticobasal syndrome.

    Directory of Open Access Journals (Sweden)

    James R Burrell

    Full Text Available BACKGROUND: Corticobasal syndrome (CBS is characterized by multifaceted motor system dysfunction and cognitive disturbance; distinctive clinical features include limb apraxia and visuospatial dysfunction. Transcranial magnetic stimulation (TMS has been used to study motor system dysfunction in CBS, but the relationship of TMS parameters to clinical features has not been studied. The present study explored several hypotheses; firstly, that limb apraxia may be partly due to visuospatial impairment in CBS. Secondly, that motor system dysfunction can be demonstrated in CBS, using threshold-tracking TMS, and is linked to limb apraxia. Finally, that atrophy of the primary motor cortex, studied using voxel-based morphometry analysis (VBM, is associated with motor system dysfunction and limb apraxia in CBS. METHODS: Imitation of meaningful and meaningless hand gestures was graded to assess limb apraxia, while cognitive performance was assessed using the Addenbrooke's Cognitive Examination - Revised (ACE-R, with particular emphasis placed on the visuospatial subtask. Patients underwent TMS, to assess cortical function, and VBM. RESULTS: In total, 17 patients with CBS (7 male, 10 female; mean age 64.4+/- 6.6 years were studied and compared to 17 matched control subjects. Of the CBS patients, 23.5% had a relatively inexcitable motor cortex, with evidence of cortical dysfunction in the remaining 76.5% patients. Reduced resting motor threshold, and visuospatial performance, correlated with limb apraxia. Patients with a resting motor threshold <50% performed significantly worse on the visuospatial sub-task of the ACE-R than other CBS patients. Cortical function correlated with atrophy of the primary and pre-motor cortices, and the thalamus, while apraxia correlated with atrophy of the pre-motor and parietal cortices. CONCLUSIONS: Cortical dysfunction appears to underlie the core clinical features of CBS, and is associated with atrophy of the primary motor and

  16. Fundamentals of ServCat

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This training manual for the U.S. Fish and Wildlife Service Catalog (ServCat) provides detailed instructions on searching for records, creating records, and...

  17. NRPC ServCat priorities

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document lists the Natural Resource Program Centers priority ServCat documents. It is recommended that these documents which include annual narrative reports,...

  18. Effect of stimulation of trigeminal ganglion on regional cerebral blood flow in cats

    International Nuclear Information System (INIS)

    Regional cerebral blood flow was studied in the cat, with and without trigeminal ganglion stimulation, by the intravenous injection of the tracer [14C]iodoantipyrine and subsequent regional brain dissection. Electrical activation of the trigeminal ganglion led to a selective increase in regional blood flow in the frontal and parietal cortex that was bilateral without change in the posterior cortex, deep cerebral nuclei, white matter, or brain stem. Unilateral intracranial section of the facial nerve blocked the response in the ipsilateral frontal and parietal cortex, whereas bilateral facial nerve section blocked the contralateral frontal cortical response. The contralateral parietal cortical increase in blood flow was not affected by facial nerve section and may thus represent the result of metabolic activation of sensory cortex

  19. Properties of squeezed Schroedinger cats

    International Nuclear Information System (INIS)

    In this article we investigate some statistical properties of the even and odd squeezed (squeezed Schroedinger cat) states. The quasi-probability distribution functions especially W(α) and Q(α) are calculated and discussed for these states. The phase distribution function is discussed. A generation scheme is proposed for either the squeezed generalized Schroedinger cat, or the squeezed number state. (author). 35 refs, 5 figs

  20. Seizures and epilepsy in cats

    OpenAIRE

    Moore SA

    2014-01-01

    Sarah A Moore Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, USA Abstract: Seizures are a common presenting complaint in cats, although causes and options for the treatment of seizures in this species have been historically poorly described in the veterinary literature. Seizure manifestation in cats may be different than what is typically seen in dogs, but the underlying causes of seizure activity are the same. These include primary epilepsies, structura...

  1. Echocardiographic Findings in 11 Cats with Acromegaly

    OpenAIRE

    Myers, J A; Lunn, K.F.; Bright, J.M.

    2014-01-01

    Background Information regarding cardiac changes in domestic cats with acromegaly is limited. Hypothesis/Objectives The objective of this study was to describe the echocardiographic findings in cats with acromegaly. Animals Eighteen cats diagnosed with acromegaly at Colorado State University between 2008 and 2012. Of these 18 cats, 11 had echocardiography performed. Methods A retrospective review of medical records was made to identify cats with acromegaly that also had echocardiography perfo...

  2. Schrodinger's cat: much ado about nothing

    CERN Document Server

    Ionicioiu, Radu

    2016-01-01

    In this note I briefly discuss the Schrodinger's cat Gedankenexperiment. By analysing the information flow in the system I show that no entanglement exists between the atom and the cat. The atom and the cat are connected only through a classical information channel (detector clicks $\\rightarrow$ poison is released $\\rightarrow$ cat is dead). No amount of local operations and classical communication can entangle the atom and the cat. Consequently, the paradox disappears.

  3. Acquired retinal folds in the cat.

    Science.gov (United States)

    MacMillan, A D

    1976-06-01

    Retinal folds were found in 5 cats. The apparent cause of the folding was varied: in 1 cat the folds appeared after a localized retinal detachment; in 2 cats the condition accompanied other intraocular abnormalities associated with feline infectious peritonitis; 1 cat had active keratitis, and the retinal changes were thought to have been injury related; and 1 cat, bilaterally affected, had chronic glomerulonephritis. PMID:945253

  4. Primary hypoadrenocorticism in ten cats.

    Science.gov (United States)

    Peterson, M E; Greco, D S; Orth, D N

    1989-01-01

    Primary hypoadrenocorticism was diagnosed in ten young to middle-aged cats of mixed breeding. Five of the cats were male, and five were female. Historic signs included lethargy (n = 10), anorexia (n = 10), weight loss (n = 9), vomiting (n = 4), and polyuria (n = 3). Dehydration (n = 9), hypothermia (n = 8), prolonged capillary refill time (n = 5), weak pulse (n = 5), collapse (n = 3), and sinus bradycardia (n = 2) were found on physical examination. Results of initial laboratory tests revealed anemia (n = 3), absolute lymphocytosis (n = 2), absolute eosinophilia (n = 1), and azotemia and hyperphosphatemia (n = 10). Serum electrolyte changes included hyponatremia (n = 10), hyperkalemia (n = 9), hypochloremia (n = 9), and hypercalcemia (n = 1). The diagnosis of primary adrenocortical insufficiency was established on the basis of results of adrenocorticotropic hormone (ACTH) stimulation tests (n = 10) and endogenous plasma ACTH determinations (n = 7). Initial therapy for hypoadrenocorticism included intravenous administration of 0.9% saline and dexamethasone and intramuscular administration of desoxycorticosterone acetate in oil. Three cats were euthanatized shortly after diagnosis because of poor clinical response. Results of necropsy examination were unremarkable except for complete destruction of both adrenal cortices. Seven cats were treated chronically with oral prednisone or intramuscular methylprednisolone acetate for glucocorticoid supplementation and with oral fludrocortisone acetate or intramuscular injections of repository desoxycorticosterone pivalate for mineralocorticoid replacement. One cat died after 47 days of therapy from unknown causes; the other six cats are still alive and well after 3 to 70 months of treatment. PMID:2469793

  5. La estimulación eléctrica de la corteza motora para el tratamiento del dolor central y dolor periférico por desaferentización Electrical stimulation of the motor cortex for the management of central pain and peripheral pain caused by desafferentiation

    Directory of Open Access Journals (Sweden)

    J. V. Pesudo

    2004-09-01

    Full Text Available El dolor central y el dolor periférico por desaferentización son de difícil tratamiento incluso con fármacos de última generación. La estimulación eléctrica sobre diversas estructuras ha demostrado en general ser poco efectiva. La estimulación sobre la corteza motora es una técnica relativamente nueva que parece ofrecer resultados prometedores en estos cuadros. Aunque desde el punto de vista quirúrgico es una técnica sencilla, no lo es tanto la localización adecuada de la corteza motora, lo cual es una condición importante para su efectividad. En este trabajo ofrecemos una revisión bibliográfica sobre ella. Sus indicaciones fundamentales actualmente son el dolor central fundamentalmente talámico, y el dolor trigeminal por desaferentización. La respuesta a barbitúricos sin respuesta a opioides, la conservación relativa de las vías motoras y sensitivas, y la respuesta a la estimulación magnética transcraneal predicen un buen resultado. Diversos métodos son utilizados para determinar la zona a estimular: PESS, estimulación intraoperatoria, neuronavegación, RNM funcional. Los parámetros de estimulación recomendados varían de unos autores a otros. Su mecanismo de actuación no es en la actualidad bien conocido aunque las teorías más aceptadas son la activación de zonas que modulan el dolor y la inhibición de la transmisión de los estímulos nociceptivos a nivel medular.Central pain and peripheral pain caused by desafferentation are difficult to treat even with last generation drugs. Electric stimulation of several structures has shown to be scarcely effective in general. Stimulation of motor cortex is a relatively new technique that seems to offer promising results in these disorders. While it is a simple technique from the surgical point of view, the adequate location of the motor cortex is not so easy, this being a significant condition for its effectiveness. In this paper we review the literature that has been

  6. Mesotelioma pleural com metástase renal em gato Pleural mesothelioma with renal metastasis in a cat

    Directory of Open Access Journals (Sweden)

    A.M. Piacenti

    2004-08-01

    Full Text Available It has been described the anatomopathological and immunohistochemical characteristics of a multinodular neoplasm distributed in the parietal and visceral pleurae, pericardium, thoracic portion of the diaphragm and renal cortex of an eight year-old, female, mixed breed, cat. Based on the anatomopathological and immunohistochemical findings it was firmed the diagnosis of biphasic pleural mesotelioma with renal metastasis.

  7. The effects of stimulation of the anterior cingulate gyrus in cats with freedom of movement

    Science.gov (United States)

    Dapres, G.; Cadilhac, J.; Passouant, P.

    1980-01-01

    Stimuli of varying strength, frequency and duration were applied to the anterior cingulate gyrus in unanesthetized cats with freedom of movement. The motor, vegetative and electrical effects of these stimuli, although inconstant, lead to a consideration of the role of this structure in the extrapyramidal control of motricity.

  8. Regulating prefrontal cortex activation

    DEFF Research Database (Denmark)

    Aznar, Susana; Klein, Anders Bue

    2013-01-01

    The prefrontal cortex (PFC) is involved in mediating important higher-order cognitive processes such as decision making, prompting thereby our actions. At the same time, PFC activation is strongly influenced by emotional reactions through its functional interaction with the amygdala and the stria...

  9. [Muscle stretching and unloading reflexes during cortically evoked movements in unanesthetized cats].

    Science.gov (United States)

    Kostiukov, A I; Tal'nov, A N

    1992-01-01

    Extension and flexion cortically-evoked movements (CEMs) were studied in the framework of the experimental approach developed in the previous paper [5]. Movements in the elbow joint of an unanesthetized cat were evoked by intracortical microstimulation (ICMS) applied to the motor cortex, then they were tested using a torque disturbance method. Similarity of flexion and extension CEMs allowed producing their combined quantitative analysis and comparing the obtained characteristics with those defined for the movements which were evoked by direct stimulation of the biceps and triceps muscles in an anesthetized animal. Resulting stiffness and uncertainty index (UI) served as the main characteristics of the movement in the presence of torque disturbances. Depending on the relationship between the directions of the preceding movement and the initial phase of the disturbed one, CEMs were divided into two types: coinciding (1) and opposing (2) CEMs. When the preceding movement was evoked by switching on of ICMS, both types of the disturbed movements could be considered as realizations of the phasic myotatic reflexes: unloading (1) and stretch (2). Disturbed movements of type 1 were characterized by the narrow range of mean values of UI: 0.43-0.91 (1.2 Hz wave of torque disturbance) and 0.24-0.73 (3.2 Hz). Transition to type 2 enlarged sharply the spread in the means, they could be both positive and negative, variances of UI in separate realizations significantly increased as well. It is supposed that intensity of central processes controlling the disturbed movements is mainly connected with changes in their direction but not with the movement per se. PMID:1513408

  10. Properties of slow oscillation during slow-wave sleep and anesthesia in cats.

    Science.gov (United States)

    Chauvette, Sylvain; Crochet, Sylvain; Volgushev, Maxim; Timofeev, Igor

    2011-10-19

    Deep anesthesia is commonly used as a model of slow-wave sleep (SWS). Ketamine-xylazine anesthesia reproduces the main features of sleep slow oscillation: slow, large-amplitude waves in field potential, which are generated by the alternation of hyperpolarized and depolarized states of cortical neurons. However, direct quantitative comparison of field potential and membrane potential fluctuations during natural sleep and anesthesia is lacking, so it remains unclear how well the properties of sleep slow oscillation are reproduced by the ketamine-xylazine anesthesia model. Here, we used field potential and intracellular recordings in different cortical areas in the cat to directly compare properties of slow oscillation during natural sleep and ketamine-xylazine anesthesia. During SWS cortical activity showed higher power in the slow/delta (0.1-4 Hz) and spindle (8-14 Hz) frequency range, whereas under anesthesia the power in the gamma band (30-100 Hz) was higher. During anesthesia, slow waves were more rhythmic and more synchronous across the cortex. Intracellular recordings revealed that silent states were longer and the amplitude of membrane potential around transition between active and silent states was bigger under anesthesia. Slow waves were mostly uniform across cortical areas under anesthesia, but in SWS, they were most pronounced in associative and visual areas but smaller and less regular in somatosensory and motor cortices. We conclude that, although the main features of the slow oscillation in sleep and anesthesia appear similar, multiple cellular and network features are differently expressed during natural SWS compared with ketamine-xylazine anesthesia. PMID:22016533

  11. Reported cat bites in Dallas: characteristics of the cats, the victims, and the attack events.

    OpenAIRE

    Wright, J C

    1990-01-01

    Associated with the increased popularity of cats as pets in American households has been an increase in the number of cat bites reported to health departments. Bite reports from Dallas, TX, for 1985 were analyzed for different aspects of the cat bite event, including characteristics of the cats, the people bitten, the wounds, and the attack events. Cat bites and scratches constituted 25 percent of the 2,494 reported animal bites. Biting cats were typically stray females. People 21 to 35 years...

  12. Cat Ownership Perception and Caretaking Explored in an Internet Survey of People Associated with Cats.

    Directory of Open Access Journals (Sweden)

    Sarah Zito

    Full Text Available People who feed cats that they do not perceive they own (sometimes called semi-owners are thought to make a considerable contribution to unwanted cat numbers because the cats they support are generally not sterilized. Understanding people's perception of cat ownership and the psychology underlying cat semi-ownership could inform approaches to mitigate the negative effects of cat semi-ownership. The primary aims of this study were to investigate cat ownership perception and to examine its association with human-cat interactions and caretaking behaviours. A secondary aim was to evaluate a definition of cat semi-ownership (including an association time of ≥1 month and frequent feeding, revised from a previous definition proposed in the literature to distinguish cat semi-ownership from casual interactions with unowned cats. Cat owners and semi-owners displayed similar types of interactions and caretaking behaviours. Nevertheless, caretaking behaviours were more commonly displayed towards owned cats than semi-owned cats, and semi-owned cats were more likely to have produced kittens (p<0.01. All interactions and caretaking behaviours were more likely to be displayed towards cats in semi-ownership relationships compared to casual interaction relationships. Determinants of cat ownership perception were identified (p<0.05 and included association time, attachment, perceived cat friendliness and health, and feelings about unowned cats, including the acceptability of feeding unowned cats. Encouraging semi-owners to have the cats they care for sterilized may assist in reducing the number of unwanted kittens and could be a valuable alternative to trying to prevent semi-ownership entirely. Highly accessible semi-owner "gatekeepers" could help to deliver education messages and facilitate the provision of cat sterilization services to semi-owners. This research enabled semi-ownership to be distinguished from casual interaction relationships and can assist

  13. Motor neglect.

    OpenAIRE

    Laplane, D.; Degos, J D

    1983-01-01

    Motor neglect is characterised by an underutilisation of one side, without defects of strength, reflexes or sensibility. Twenty cases of frontal, parietal and thalamic lesions causing motor neglect, but all without sensory neglect, are reported. It is proposed that the cerebral structures involved in motor neglect are the same as those for sensory neglect and for the preparation of movement. As in sensory neglect, the multiplicity of the structures concerned suggests that this interconnection...

  14. Motor syndromes.

    Science.gov (United States)

    Corea, Francesco; Micheli, Sara

    2012-01-01

    Motor disturbances alone or associated with other focal deficits are the most common symptoms suggesting a neurovascular event. An appropriate clinical assessment of these signs and symptoms may help physicians to better diagnose and to both better treat and predict outcome. In this paper the main clinical features of motor deficit are described together with other motor-related events such as ataxia and movement disturbances. PMID:22377850

  15. White matter integrity of premotor–motor connections is associated with motor output in chronic stroke patients

    Directory of Open Access Journals (Sweden)

    Robert Schulz

    2015-01-01

    Full Text Available Corticocortical functional interactions between the primary motor cortex (M1 and secondary motor areas, such as the dorsal (PMd and ventral (PMv premotor cortices and the supplementary motor area (SMA are relevant for residual motor output after subcortical stroke. We hypothesized that the microstructural integrity of the underlying white matter tracts also plays a role in preserved motor output. Using diffusion-tensor imaging we aimed at (i reconstructing individual probable intrahemispheric connections between M1 and the three secondary areas (PMd, PMv, SMA and (ii examining the extent to which the tract-related microstructural integrity correlates with residual motor output. The microstructural integrity of the tract connecting ipsilesional M1 and PMd was significantly associated with motor output (R = 0.78, P = 0.02. The present results support the view that ipsilesional secondary motor areas such as the PMd might support M1 via corticocortical connections to generate motor output after stroke.

  16. Repetitive Transcranial Direct Current Stimulation Induced Excitability Changes of Primary Visual Cortex and Visual Learning Effects—A Pilot Study

    OpenAIRE

    Sczesny-Kaiser, Matthias; Beckhaus, Katharina; Dinse, Hubert R.; Schwenkreis, Peter; Tegenthoff, Martin; Höffken, Oliver

    2016-01-01

    Studies on noninvasive motor cortex stimulation and motor learning demonstrated cortical excitability as a marker for a learning effect. Transcranial direct current stimulation (tDCS) is a non-invasive tool to modulate cortical excitability. It is as yet unknown how tDCS-induced excitability changes and perceptual learning in visual cortex correlate. Our study aimed to examine the influence of tDCS on visual perceptual learning in healthy humans. Additionally, we measured excitability in prim...

  17. Interactive visuo-motor therapy system for stroke rehabilitation

    OpenAIRE

    Eng, K; Siekierka, E; Pyk, P; Chevrier, E; Hauser, Y; Holper, L; Cameirao, M; Hägni, K; Zimmerli, L; Duff, A.; Schuster, C.; Bassetti, C.; Verschure, P; Kiper, D.

    2007-01-01

    We present a virtual reality (VR)-based motor neurorehabilitation system for stroke patients with upper limb paresis. It is based on two hypotheses: (1) observed actions correlated with self-generated or intended actions engage cortical motor observation, planning and execution areas (mirror neurons); (2) activation in damaged parts of motor cortex can be enhanced by viewing mirrored movements of non-paretic limbs. We postulate that our approach, applied during the acute post-stroke phase, fa...

  18. Neural Correlates of an Auditory Afterimage in Primary Auditory Cortex

    OpenAIRE

    Noreña, A. J.; Eggermont, J. J.

    2003-01-01

    The Zwicker tone (ZT) is defined as an auditory negative afterimage, perceived after the presentation of an appropriate inducer. Typically, a notched noise (NN) with a notch width of 1/2 octave induces a ZT with a pitch falling in the frequency range of the notch. The aim of the present study was to find potential neural correlates of the ZT in the primary auditory cortex of ketamine-anesthetized cats. Responses of multiunits were recorded simultaneously with two 8-electrode arrays during 1 s...

  19. Synchronization of oscillatory neuronal responses between striate and extrastriate visual cortical areas of the cat.

    OpenAIRE

    Engel, A K; Kreiter, A K; König, P; Singer, W.

    1991-01-01

    Recent studies have shown that neurons in area 17 of cat visual cortex display oscillatory responses which can synchronize across spatially separate orientation columns. Here, we demonstrate that unit responses recorded from the posteromedial lateral suprasylvian area, a visual association area specialized for the analysis of motion, also exhibit an oscillatory temporal structure. Cross-correlation analysis of unit responses reveals that cells in area 17 and the posteromedial lateral suprasyl...

  20. On Schr\\"odinger's cat

    CERN Document Server

    de Silva, Nalin

    2010-01-01

    Schr\\"odinger's cat appears to have been harassed in a chamber during the past eighty years or so by interpreting the role of the observer as a person, who sets an experiment and then observes results, may be after some time. The realist position tells us that the physical processes would take place independent of the observer with well defined properties, whereas the positivist position wants us to believe that nothing can be said of a system when it is not being observed. In this paper we question both these positions and also the assumption that the atom and the cat are entangled and further whether the atom could be considered to be in a state of decay and not decay. We let the cat either out of the bag (chamber) or rest in peace with or without the atom or the observer.

  1. Cat Ownership Perception and Caretaking Explored in an Internet Survey of People Associated with Cats.

    Science.gov (United States)

    Zito, Sarah; Vankan, Dianne; Bennett, Pauleen; Paterson, Mandy; Phillips, Clive J C

    2015-01-01

    People who feed cats that they do not perceive they own (sometimes called semi-owners) are thought to make a considerable contribution to unwanted cat numbers because the cats they support are generally not sterilized. Understanding people's perception of cat ownership and the psychology underlying cat semi-ownership could inform approaches to mitigate the negative effects of cat semi-ownership. The primary aims of this study were to investigate cat ownership perception and to examine its association with human-cat interactions and caretaking behaviours. A secondary aim was to evaluate a definition of cat semi-ownership (including an association time of ≥1 month and frequent feeding), revised from a previous definition proposed in the literature to distinguish cat semi-ownership from casual interactions with unowned cats. Cat owners and semi-owners displayed similar types of interactions and caretaking behaviours. Nevertheless, caretaking behaviours were more commonly displayed towards owned cats than semi-owned cats, and semi-owned cats were more likely to have produced kittens (pcats in semi-ownership relationships compared to casual interaction relationships. Determinants of cat ownership perception were identified (pcat friendliness and health, and feelings about unowned cats, including the acceptability of feeding unowned cats. Encouraging semi-owners to have the cats they care for sterilized may assist in reducing the number of unwanted kittens and could be a valuable alternative to trying to prevent semi-ownership entirely. Highly accessible semi-owner "gatekeepers" could help to deliver education messages and facilitate the provision of cat sterilization services to semi-owners. This research enabled semi-ownership to be distinguished from casual interaction relationships and can assist welfare and government agencies to identify cat semi-owners in order to develop strategies to address this source of unwanted cats. PMID:26218243

  2. Cognition without Cortex.

    Science.gov (United States)

    Güntürkün, Onur; Bugnyar, Thomas

    2016-04-01

    Assumptions on the neural basis of cognition usually focus on cortical mechanisms. Birds have no cortex, but recent studies in parrots and corvids show that their cognitive skills are on par with primates. These cognitive findings are accompanied by neurobiological discoveries that reveal avian and mammalian forebrains are homologous, and show similarities in connectivity and function down to the cellular level. But because birds have a large pallium, but no cortex, a specific cortical architecture cannot be a requirement for advanced cognitive skills. During the long parallel evolution of mammals and birds, several neural mechanisms for cognition and complex behaviors may have converged despite an overall forebrain organization that is otherwise vastly different. PMID:26944218

  3. Lower motor neuron findings after upper motor neuron injury: Insights from postoperative supplementary motor area syndrome

    Directory of Open Access Journals (Sweden)

    Jeffrey E Florman

    2013-03-01

    Full Text Available Hypertonia and hypereflexia are classically described responses to upper motor neuron injury. However, acute hypotonia and areflexia with motor deficit are hallmark findings after many central nervous system insults such as acute stroke and spinal shock. Historic theories to explain these contradictory findings have implicated a number of potential mechanisms mostly relying on the loss of descending corticospinal input as the underlying etiology. Unfortunately, these simple descriptions consistently fail to adequately explain the pathophysiology and connectivity leading to acute hyporeflexia and delayed hypereflexia that result from such insult. This article highlights the common observation of acute hyporeflexia after central nervous system insults and explores the underlying anatomy and physiology. Further, evidence for the underlying connectivity is presented and implicates the dominant role of supraspinal inhibitory influence originating in the supplementary motor area descending through the corticospinal tracts. Unlike traditional explanations, this theory more adequately explains the findings of postoperative supplementary motor area syndrome in which hyporeflexive motor deficit is observed acutely in the face of intact primary motor cortex connections to the spinal cord. Further, the proposed connectivity can be generalized to help explain other insults including stroke, atonic seizures, and spinal shock.

  4. Spatial Stream Segregation by Cats.

    Science.gov (United States)

    Javier, Lauren K; McGuire, Elizabeth A; Middlebrooks, John C

    2016-06-01

    Listeners can perceive interleaved sequences of sounds from two or more sources as segregated streams. In humans, physical separation of sound sources is a major factor enabling such stream segregation. Here, we examine spatial stream segregation with a psychophysical measure in domestic cats. Cats depressed a pedal to initiate a target sequence of brief sound bursts in a particular rhythm and then released the pedal when the rhythm changed. The target bursts were interleaved with a competing sequence of bursts that could differ in source location but otherwise were identical to the target bursts. This task was possible only when the sources were heard as segregated streams. When the sound bursts had broad spectra, cats could detect the rhythm change when target and competing sources were separated by as little as 9.4°. Essentially equal levels of performance were observed when frequencies were restricted to a high, 4-to-25-kHz, band in which the principal spatial cues presumably were related to sound levels. When the stimulus band was restricted from 0.4 to 1.6 kHz, leaving interaural time differences as the principal spatial cue, performance was severely degraded. The frequency sensitivity of cats in this task contrasts with that of humans, who show better spatial stream segregation with low- than with high-frequency sounds. Possible explanations for the species difference includes the smaller interaural delays available to cats due to smaller sizes of their heads and the potentially greater sound-level cues available due to the cat's frontally directed pinnae and higher audible frequency range. PMID:26993807

  5. Somatotopic Semantic Priming and Prediction in the Motor System.

    Science.gov (United States)

    Grisoni, Luigi; Dreyer, Felix R; Pulvermüller, Friedemann

    2016-05-01

    The recognition of action-related sounds and words activates motor regions, reflecting the semantic grounding of these symbols in action information; in addition, motor cortex exerts causal influences on sound perception and language comprehension. However, proponents of classic symbolic theories still dispute the role of modality-preferential systems such as the motor cortex in the semantic processing of meaningful stimuli. To clarify whether the motor system carries semantic processes, we investigated neurophysiological indexes of semantic relationships between action-related sounds and words. Event-related potentials revealed that action-related words produced significantly larger stimulus-evoked (Mismatch Negativity-like) and predictive brain responses (Readiness Potentials) when presented in body-part-incongruent sound contexts (e.g., "kiss" in footstep sound context; "kick" in whistle context) than in body-part-congruent contexts, a pattern reminiscent of neurophysiological correlates of semantic priming. Cortical generators of the semantic relatedness effect were localized in areas traditionally associated with semantic memory, including left inferior frontal cortex and temporal pole, and, crucially, in motor areas, where body-part congruency of action sound-word relationships was indexed by a somatotopic pattern of activation. As our results show neurophysiological manifestations of action-semantic priming in the motor cortex, they prove semantic processing in the motor system and thus in a modality-preferential system of the human brain. PMID:26908635

  6. Basic electrophysiological properties of spinal cord motoneurons during old age in the cat.

    Science.gov (United States)

    Morales, F R; Boxer, P A; Fung, S J; Chase, M H

    1987-07-01

    1. The electrophysiological properties of alpha-motoneurons in old cats (14-15 yr) were compared with those of adult cats (1-3 yr). These properties were measured utilizing intracellular recording and stimulating techniques. 2. Unaltered in the old cat motoneurons were the membrane potential, action potential amplitude, and slopes of the initial segment (IS) and soma dendritic (SD) spikes, as well as the duration and amplitude of the action potential's afterhyperpolarization. 3. In contrast, the following changes in the electrophysiological properties of lumbar motoneurons were found in the old cats: a decrease in axonal conduction velocity, a shortening of the IS-SD delay, an increase in input resistance, and a decrease in rheobase. 4. In spite of these considerable changes in motoneuron properties in the old cat, normal correlations between different electrophysiological properties were maintained. The following key relationships, among others, were the same in adult and old cat motoneurons: membrane potential polarization versus action potential amplitude, duration of the afterhyperpolarization versus motor axon conduction velocity, and rheobase versus input conductance. 5. A review of the existing literature reveals that neither chronic spinal cord section nor deafferentation (13, 21) in adult animals produce the changes observed in old cats. Thus we consider it unlikely that a loss of synaptic contacts was responsible for the modifications in electrophysiological properties observed in old cat motoneurons. 6. We conclude that during old age there are significant changes in the soma-dendritic portion of cat motoneurons, as indicated by the modifications found in input resistance, rheobase, and IS-SD delay, as well as significant changes in their axons, as indicated by a decrease in conduction velocity. PMID:3612223

  7. The Nucleon as a Holographic Cheshire Cat

    OpenAIRE

    Zahed, Ismail

    2014-01-01

    The Cheshire cat principle emerges naturally from the holographic approach of the nucleon in terms of a bulk instanton. The cat hides in the holographic direction. I briefly review the one-nucleon problem in the holographic limit.

  8. The nucleon as a holographic Cheshire cat

    International Nuclear Information System (INIS)

    The Cheshire cat principle emerges naturally from the holographic approach of the nucleon in terms of a bulk instanton. The cat hides in the holographic direction. I briefly review the one-nucleon problem in the holographic limit

  9. Cerebral cysticercosis in a cat : clinical communication

    Directory of Open Access Journals (Sweden)

    E.V. Schwan

    2002-07-01

    Full Text Available The metacestode of Taenia solium, Cysticercus cellulosae, was recovered from the brain of a cat showing central nervous clinical signs ante mortem. This is the first record of cerebral cysticercosis in a cat in South Africa.

  10. Osteolysis in cat-scratch fever

    International Nuclear Information System (INIS)

    The osteolysis associated with cat-scratch fever resembles more ominous conditions. The combination of osteolysis and unilateral regional adenopathy in a child or adolescent should suggest cat-scratch disease. Bone scans and CT verified the diagnosis

  11. Dipylidium (Dog and Cat Flea Tapeworm) FAQs

    Science.gov (United States)

    ... if my pet has a tapeworm infection? Although cats and dogs are rarely ill as a result of a ... and outdoor environments. Have your veterinarian treat your dogs and cats promptly if they have tapeworms. Clean up after ...

  12. ServCat Document Selection Guidelines

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The ServCat document selection guidelines were developed for selecting appropriate documents to upload into ServCat. When beginning to upload documents into...

  13. Supplementary Motor Complex and Disturbed Motor Control – a Retrospective Clinical and Lesion Analysis of Patients after Anterior Cerebral Artery Stroke

    OpenAIRE

    Brugger, Florian; Galovic, Marian; Weder, Bruno J.; Kägi, Georg

    2015-01-01

    Background Both the supplementary motor complex (SMC), consisting of the supplementary motor area (SMA) proper, the pre-SMA, and the supplementary eye field, and the rostral cingulate cortex are supplied by the anterior cerebral artery (ACA) and are involved in higher motor control. The Bereitschaftspotential (BP) originates from the SMC and reflects cognitive preparation processes before volitional movements. ACA strokes may lead to impaired motor control in the absence of limb weakness a...

  14. Cerebellar networks with the cerebral cortex and basal ganglia.

    Science.gov (United States)

    Bostan, Andreea C; Dum, Richard P; Strick, Peter L

    2013-05-01

    The dominant view of cerebellar function has been that it is exclusively concerned with motor control and coordination. Recent findings from neuroanatomical, behavioral, and imaging studies have profoundly changed this view. Neuroanatomical studies using virus transneuronal tracers have demonstrated that cerebellar output reaches vast areas of the neocortex, including regions of prefrontal and posterior parietal cortex. Furthermore, it has recently become clear that the cerebellum is reciprocally connected with the basal ganglia, which suggests that the two subcortical structures are part of a densely interconnected network. Taken together, these findings elucidate the neuroanatomical substrate for cerebellar involvement in non-motor functions mediated by the prefrontal and posterior parietal cortex, as well as in processes traditionally associated with the basal ganglia. PMID:23579055

  15. Dirac Cat States in Relativistic Landau Levels

    OpenAIRE

    Bermudez, A.; Martin-Delgado, M. A.; Solano, E.

    2007-01-01

    We show that a relativistic version of Schrodinger cat states, here called Dirac cat states, can be built in relativistic Landau levels when an external magnetic field couples to a relativistic spin 1/2 charged particle. Under suitable initial conditions, the associated Dirac equation produces unitarily Dirac cat states involving the orbital quanta of the particle in a well defined mesoscopic regime. We demonstrate that the proposed Dirac cat states have a purely relativistic origin and cease...

  16. Halal Cat Food for the World Market

    OpenAIRE

    Amir H.M.S; Razauden Z; Harisun Y; Ida I.M; Mona Z

    2014-01-01

    Currently, University Technology Malaysia (UTM) is engaged with a well-known private company in Malaysia to develop halal cat food for the world. A team of scientists from UTM was formed for the development of cat food from preparing palatants to producing canned cat and kibbled cat food formulation on a commercial scale to fulfil the vast market demand, as well as to act as contract manufacturer for this private company. Financial aid is made available by the university and Malaysian governm...

  17. Motor homopolar

    OpenAIRE

    2007-01-01

    Mostramos la construcción de un modelo de motor homopolar, uno de los más antiguos tipos de motores eléctricos. Se caracterizan porque el campo magnético del imán mantiene siempre la misma polaridad (de ahí su nombre, del griego homos, igual), de modo que, cuando una corriente eléctrica atraviesa el campo magnético, aparece una fuerza que hace girar los elementos no fijados mecánicamente. En el sencillísimo motor homopolar colgado (Schlichting y Ucke 2004), el imán puede girar ...

  18. Application of stepping motor

    International Nuclear Information System (INIS)

    This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

  19. Cats & Dogs%猫狗大战

    Institute of Scientific and Technical Information of China (English)

    阿萌

    2003-01-01

    @@ ( Dogs and cats are permanent enemies. A dog named Bubby is catnapped by the cats. The whole cats' world is shocked and alert. ) Dog Chairman: Gentlemen, a few moments ago I received word of the gravest nature. The key agent working the Brody case has been catnapped. Although he is safe, new must replace him as soon as possible.

  20. Decoding bipedal locomotion from the rat sensorimotor cortex

    Science.gov (United States)

    Rigosa, J.; Panarese, A.; Dominici, N.; Friedli, L.; van den Brand, R.; Carpaneto, J.; DiGiovanna, J.; Courtine, G.; Micera, S.

    2015-10-01

    Objective. Decoding forelimb movements from the firing activity of cortical neurons has been interfaced with robotic and prosthetic systems to replace lost upper limb functions in humans. Despite the potential of this approach to improve locomotion and facilitate gait rehabilitation, decoding lower limb movement from the motor cortex has received comparatively little attention. Here, we performed experiments to identify the type and amount of information that can be decoded from neuronal ensemble activity in the hindlimb area of the rat motor cortex during bipedal locomotor tasks. Approach. Rats were trained to stand, step on a treadmill, walk overground and climb staircases in a bipedal posture. To impose this gait, the rats were secured in a robotic interface that provided support against the direction of gravity and in the mediolateral direction, but behaved transparently in the forward direction. After completion of training, rats were chronically implanted with a micro-wire array spanning the left hindlimb motor cortex to record single and multi-unit activity, and bipolar electrodes into 10 muscles of the right hindlimb to monitor electromyographic signals. Whole-body kinematics, muscle activity, and neural signals were simultaneously recorded during execution of the trained tasks over multiple days of testing. Hindlimb kinematics, muscle activity, gait phases, and locomotor tasks were decoded using offline classification algorithms. Main results. We found that the stance and swing phases of gait and the locomotor tasks were detected with accuracies as robust as 90% in all rats. Decoded hindlimb kinematics and muscle activity exhibited a larger variability across rats and tasks. Significance. Our study shows that the rodent motor cortex contains useful information for lower limb neuroprosthetic development. However, brain-machine interfaces estimating gait phases or locomotor behaviors, instead of continuous variables such as limb joint positions or speeds

  1. Genitourinary dysplasia in a cat

    International Nuclear Information System (INIS)

    A six-month-old kitten had congenital urethral sphincter mechanism incompetence due to urethral hypoplasia and associated uterine hypoplasia and vaginal aplasia. Diagnosis was based on radiographic examination, surgical exploration and histological examination of the lower urinary tract. Surgical correction resulted in a marked clinical improvement. The cat became fully continent following treatment with phenylpropanolamine

  2. Lessons from the Cheshire Cat

    Science.gov (United States)

    Tinberg, Donna

    2012-01-01

    "If you don't know where you're going, any road will take you there." This oft-cited but not-quite-accurate quote is from the Lewis Carroll's classic children's tale, Alice in Wonderland. In Carroll's altered reality, the conversation between the disoriented Alice and the mysterious Cheshire Cat actually went like this: "Would you tell me, please,…

  3. A strange cat in Dublin

    Science.gov (United States)

    O'Raifeartaigh, Cormac

    2012-11-01

    Not many life stories in physics involve Nazis, illicit sex, a strange cat and the genetic code. Thus, a new biography of the great Austrian physicist Erwin Schrödinger is always of interest, and with Erwin Schrödinger and the Quantum Revolution, veteran science writer John Gribbin does not disappoint.

  4. Lymphoplasmacytic gingivitis in a cat

    OpenAIRE

    Baird, Kristin

    2005-01-01

    A 12-year-old male neutered short haired cat was presented due to difficulty eating and pawing at the face. Examination revealed severe gingivitis and stomatitis throughout the oral cavity. Gingival biopsy provided a diagnosis of lymphoplasmacytic stomatitis. Extraction of all premolars and molars resulted in elimination of all clinical signs.

  5. Cat-scratch disease osteomyelitis

    International Nuclear Information System (INIS)

    We report on a patient who presented with osteomyelitis of a rib and adjacent abscess as a rare and atypical manifestation of cat-scratch disease. Radiographic findings showed an osteolytic lesion with adjacent mass. Biopsy, serology and polymerase chain reaction technique are essential for the final diagnosis. Prognosis is excellent with full recovery. (orig.)

  6. Effects of medetomidine and ketamine on the regional cerebral blood flow in cats: a SPECT study.

    Science.gov (United States)

    Waelbers, T; Peremans, K; Vermeire, S; Piron, K; Doom, M; Boer, V O; de Leeuw, H; Vente, M A D; Dobbeleir, A; Gielen, I; Audenaert, K; Polis, I

    2012-04-01

    Brain perfusion can be investigated using single photon emission computed tomography (SPECT) and the intravenous injection of (99m)technetium ethyl cysteinate dimer ((99m)Tc-ECD). However, sedation using medetomidine, an α(2)-agonist, or anaesthesia using medetomidine and ketamine, an N-methyl-d-aspartate-(NMDA)-antagonist, may be required for SPECT studies in cats but can affect the regional cerebral blood flow (rCBF). The effects of medetomidine, with or without ketamine, on regional brain perfusion were therefore investigated in six cats under three conditions. Injection of tracer occurred before sedation or anaesthesia (condition A), following intramuscular (IM) sedation with medetomidine (condition M) or after IM anaesthesia with medetomidine and ketamine (condition MK). Medetomidine and medetomidine with ketamine caused a significantly higher total tracer uptake in all brain regions. Semi-quantification of brain perfusion gave lower perfusion indices in several sub-cortical regions in conditions M and MK, compared to A. Left-right differences were observed in the temporal cortex (A), the temporal, parietal cortex and the thalamus (M) and the frontal cortex (MK). A significantly higher perfusion index in the sub-cortical regions, compared to the whole cortex, was only present in condition A. This study showed that caution is needed when quantifying brain perfusion indices when using sedative or anaesthetic agents that may affect rCBF. PMID:21636298

  7. Opposing effects of dopamine antagonism in a motor sequence task - tiapride increases cortical excitability and impairs motor learning

    Directory of Open Access Journals (Sweden)

    Silke Lissek

    2014-06-01

    Full Text Available The dopaminergic system is involved in learning and participates in the modulation of cortical excitability (CE. CE has been suggested as a marker of learning and use-dependent plasticity. However, results from separate studies on either motor CE or motor learning challenge this notion, suggesting opposing effects of dopaminergic modulation upon these parameters: while agonists decrease and antagonists increase CE, motor learning is enhanced by agonists and disturbed by antagonists. To examine whether this discrepancy persists when complex motor learning and motor CE are measured in the same experimental setup, we investigated the effects of dopaminergic (DA antagonism upon both parameters and upon task-associated brain activation. Our results demonstrate that DA-antagonism has opposing effects upon motor CE and motor sequence learning. Tiapride did not alter baseline CE, but increased CE post training of a complex motor sequence while simultaneously impairing motor learning. Moreover, tiapride reduced activation in several brain regions associated with motor sequence performance, i.e. dorsolateral PFC, supplementary motor area, Broca's area, cingulate and caudate body. Blood-oxygenation-level-dependent ( BOLD intensity in anterior cingulate and caudate body, but not CE, correlated with performance across groups. In summary, our results do not support a concept of CE as a general marker of motor learning, since they demonstrate that a straightforward relation of increased CE and higher learning success does not apply to all instances of motor learning. At least for complex motor tasks that recruit a network of brain regions outside motor cortex, CE in primary motor cortex is probably no central determinant for learning success.

  8. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  9. The use of high-density EEG to map out cortical motor activity and reorganization following lower-limb amputation

    OpenAIRE

    Valur Guðnason 1991

    2016-01-01

    Introduction: Studies have shown that after amputation, changes occur in the sensory and motor cortex. These changes are called cortical reorganization, where adjacent cortical areas occupy the cortical area of the amputated limb. High-density electroencephalography (EEG) has been used to observe cortical reorganization in the motor cortex following upper limb amputation. The aim of this study was to use high-density EEG to map out motor cortical activity and cortical reorganization following...

  10. Dietary dissolution of urinary calculi in cats

    International Nuclear Information System (INIS)

    A young adult, castrated male DSH cat was admitted for pollakiuria, hematuria and dysuria. The cat was being fed a commercial dry grocery brand cat food. Radiographs demonstrated multiple radiodense cystic calculi and urinalysis showed hematuria but no crystalluria. A tentative diagnosis of struvite urolithiasis was made. The cat was fed s/d® Feline food exclusively. Clinical signs disappeared within a week and no calculi were visible radiographically within three weeks. s/d® Feline food was continued an additional two weeks. This case study shows that s/d® Feline therapeutic food can be used to successfully manage struvite urolithiasis in cats

  11. My Experience of Feeding a Cat

    Institute of Scientific and Technical Information of China (English)

    乔琳

    2006-01-01

    I liked cat very much. In my old opinion, cat was cute and gentle. One day, my friend asked me to feed the cat for him. So I went to his house in order to take care of his cat. His neighbor was an old woman. When I was doing some cleaning, the old woman asked me if I needed some help. Suddenly, the cat stretched out its sharp claws, and clawed me and bit me with its sharp teeth. WowA It was too abrupt. The old woman got scared. “It goes crazyA” I said and asked her to get out of the room, otherwise she woul...

  12. Plasticity in the sensorimotor cortex induced by Music-supported therapy in stroke patients: A TMS study

    Directory of Open Access Journals (Sweden)

    Jennifer eGrau-Sánchez

    2013-09-01

    Full Text Available Playing a musical instrument demands the engagement of different neural systems. Recent studies about the musician’s brain and musical training highlight that this activity requires the close interaction between motor and somatosensory systems. Moreover, neuroplastic changes have been reported in motor-related areas after short and long-term musical training. Because of its capacity to promote neuroplastic changes, music has been used in the context of stroke neurorehabilitation. The majority of patients suffering from a stroke have motor impairments, preventing them to live independently. Thus, there is an increasing demand for effective restorative interventions for neurological deficits. Music-supported Therapy (MST has been recently developed to restore motor deficits. We report data of a selected sample of stroke patients who have been enrolled in a MST program (1 month intense music learning. Prior to and after the therapy, patients were evaluated with different behavioral motor tests. Transcranial Magnetic Stimulation (TMS was applied to evaluate changes in the sensorimotor representations underlying the motor gains observed. Several parameters of excitability of the motor cortex were assessed as well as the cortical somatotopic representation of a muscle in the affected hand. Our results revealed that participants obtained significant motor improvements in the paretic hand and those changes were accompanied by changes in the excitability of the motor cortex. Thus, MST leads to neuroplastic changes in the motor cortex of stroke patients which may explain its efficacy.

  13. Plasticity in the sensorimotor cortex induced by Music-supported therapy in stroke patients: a TMS study.

    Science.gov (United States)

    Grau-Sánchez, Jennifer; Amengual, Julià L; Rojo, Nuria; Veciana de Las Heras, Misericordia; Montero, Jordi; Rubio, Francisco; Altenmüller, Eckart; Münte, Thomas F; Rodríguez-Fornells, Antoni

    2013-01-01

    Playing a musical instrument demands the engagement of different neural systems. Recent studies about the musician's brain and musical training highlight that this activity requires the close interaction between motor and somatosensory systems. Moreover, neuroplastic changes have been reported in motor-related areas after short and long-term musical training. Because of its capacity to promote neuroplastic changes, music has been used in the context of stroke neurorehabilitation. The majority of patients suffering from a stroke have motor impairments, preventing them to live independently. Thus, there is an increasing demand for effective restorative interventions for neurological deficits. Music-supported Therapy (MST) has been recently developed to restore motor deficits. We report data of a selected sample of stroke patients who have been enrolled in a MST program (1 month intense music learning). Prior to and after the therapy, patients were evaluated with different behavioral motor tests. Transcranial Magnetic Stimulation (TMS) was applied to evaluate changes in the sensorimotor representations underlying the motor gains observed. Several parameters of excitability of the motor cortex were assessed as well as the cortical somatotopic representation of a muscle in the affected hand. Our results revealed that participants obtained significant motor improvements in the paretic hand and those changes were accompanied by changes in the excitability of the motor cortex. Thus, MST leads to neuroplastic changes in the motor cortex of stroke patients which may explain its efficacy. PMID:24027507

  14. Prefrontal cortex involvement in creative problem solving in middle adolescence and adulthood.

    Science.gov (United States)

    Kleibeuker, Sietske W; Koolschijn, P Cédric M P; Jolles, Dietsje D; Schel, Margot A; De Dreu, Carsten K W; Crone, Eveline A

    2013-07-01

    Creative cognition, defined as the generation of new yet appropriate ideas and solutions, serves important adaptive purposes. Here, we tested whether and how middle adolescence, characterized by transformations toward life independency and individuality, is a more profitable phase than adulthood for creative cognition. Behavioral and neural differences for creative problem solving in adolescents (15-17 years) and adults (25-30 years) were measured while performing a matchstick problem task (MPT) in the scanner and the creative ability test (CAT), a visuo-spatial divergent thinking task, outside the scanner. Overall performances were comparable, although MPT performance indicated an advantage for adolescents in creative problem solving. In addition, adolescents showed more activation in lateral prefrontal cortex (ventral and dorsal) during creative problem solving compared to adults. These areas correlated with performances on the MPT and the CAT performance. We discuss that extended prefrontal cortex activation in adolescence is important for exploration and aids in creative cognition. PMID:23624336

  15. A simulated actuator driven by motor cortical signals.

    Science.gov (United States)

    Lukashin, A V; Amirikian, B R; Georgopoulos, A P

    1996-11-01

    One problem in motor control concerns the mechanism whereby the central nervous system translates the motor cortical command encoded in cell activity into a coordinated contraction of limb muscles to generate a desired motor output. This problem is closely related to the design of adaptive systems that transform neuronal signals chronically recorded from the motor cortex into the physiologically appropriate motor output of multijoint prosthetic limbs. In this study we demonstrated how this transformation can be carried out by an artificial neural network using as command signals the actual impulse activity obtained from recordings in the motor cortex of monkeys during the performance of a task that required the exertion of force in different directions. The network receives experimentally measured brain signals and recodes them into motor actions of a simulated actuator that mimics the primate arm. The actuator responds to the motor cortical commands with surprising fidelity, generating forces in close quantitative agreement with those exerted by trained monkeys, in both the temporal and spatial domains. Moreover, we show that the time-varying motor output may be controlled by the impulse activity of as few as 15 motor cortical cells. These results outline a potentially implementable computation scheme that utilizes raw neuronal signals to drive artificial mechanical systems. PMID:8981430

  16. Development of the cerebellar cortex in the mouse

    Institute of Scientific and Technical Information of China (English)

    Xiangshu Cheng; Jin Du; Dongming Yu; Qiying Jiang; Yanqiu Hu; Lei Wang; Mingshan Li; Jinbo Deng

    2011-01-01

    The cerebellum is a highly conserved structure in the central nervous system of vertebrates, and is involved in the coordination of voluntary motor behavior. Supporting this function, the cerebellar cortex presents a layered structure which requires precise spatial and temporal coordination of proliferation, migration, differentiation, and apoptosis events. The formation of the layered structure in the developing cerebellum remains unclear. The present study investigated the development of the cerebellar cortex. The results demonstrate that the primordium of the cerebellum comprises the ependymal, mantle, and marginal layers at embryonic day 12 (E12). Subsequently, the laminated cerebellar cortex undergoes cell proliferation, differentiation, and migration, and at about postnatal day 0 (P0), the cerebellar cortex presents an external granular layer, a molecular layer, a Purkinje layer, and an internal granular layer. The external granular layer is thickest at P6/7 and disappears at P20. From P0 to P30, the internal granular cells and the Purkinje cells gradually differentiate and develop until maturity. Apoptotic neurons are evident in the layered structure in the developing cerebellar cortex. The external granular layer disappears gradually because of cell migration and apoptosis. The cells of the other layers primarily undergo differentiation, development, and apoptosis.

  17. The fecal microbiome in cats with diarrhea.

    Directory of Open Access Journals (Sweden)

    Jan S Suchodolski

    Full Text Available Recent studies have revealed that microbes play an important role in the pathogenesis of gastrointestinal (GI diseases in various animal species, but only limited data is available about the microbiome in cats with GI disease. The aim of this study was to evaluate the fecal microbiome in cats with diarrhea. Fecal samples were obtained from healthy cats (n = 21 and cats with acute (n = 19 or chronic diarrhea (n = 29 and analyzed by sequencing of 16S rRNA genes, and PICRUSt was used to predict the functional gene content of the microbiome. Linear discriminant analysis (LDA effect size (LEfSe revealed significant differences in bacterial groups between healthy cats and cats with diarrhea. The order Burkholderiales, the families Enterobacteriaceae, and the genera Streptococcus and Collinsella were significantly increased in diarrheic cats. In contrast the order Campylobacterales, the family Bacteroidaceae, and the genera Megamonas, Helicobacter, and Roseburia were significantly increased in healthy cats. Phylum Bacteroidetes was significantly decreased in cats with chronic diarrhea (>21 days duration, while the class Erysipelotrichi and the genus Lactobacillus were significantly decreased in cats with acute diarrhea. The observed changes in bacterial groups were accompanied by significant differences in functional gene contents: metabolism of fatty acids, biosynthesis of glycosphingolipids, metabolism of biotin, metabolism of tryptophan, and ascorbate and aldarate metabolism, were all significantly (p<0.001 altered in cats with diarrhea. In conclusion, significant differences in the fecal microbiomes between healthy cats and cats with diarrhea were identified. This dysbiosis was accompanied by changes in bacterial functional gene categories. Future studies are warranted to evaluate if these microbial changes correlate with changes in fecal concentrations of microbial metabolites in cats with diarrhea for the identification of potential diagnostic or

  18. Spindle Bursts in Neonatal Rat Cerebral Cortex.

    Science.gov (United States)

    Yang, Jenq-Wei; Reyes-Puerta, Vicente; Kilb, Werner; Luhmann, Heiko J

    2016-01-01

    Spontaneous and sensory evoked spindle bursts represent a functional hallmark of the developing cerebral cortex in vitro and in vivo. They have been observed in various neocortical areas of numerous species, including newborn rodents and preterm human infants. Spindle bursts are generated in complex neocortical-subcortical circuits involving in many cases the participation of motor brain regions. Together with early gamma oscillations, spindle bursts synchronize the activity of a local neuronal network organized in a cortical column. Disturbances in spindle burst activity during corticogenesis may contribute to disorders in cortical architecture and in the activity-dependent control of programmed cell death. In this review we discuss (i) the functional properties of spindle bursts, (ii) the mechanisms underlying their generation, (iii) the synchronous patterns and cortical networks associated with spindle bursts, and (iv) the physiological and pathophysiological role of spindle bursts during early cortical development. PMID:27034844

  19. Constructing Visual Perception of Body Movement with the Motor Cortex.

    OpenAIRE

    Orgs, Guido; Dovern, Anna; Hagura, Nobuhiro; Haggard, Patrick; Fink, Gereon R.; Weiss, Peter H.

    2016-01-01

    The human brain readily perceives fluent movement from static input. Using functional magnetic resonance imaging, we investigated brain mechanisms that mediate fluent apparent biological motion (ABM) perception from sequences of body postures. We presented body and nonbody stimuli varying in objective sequence duration and fluency of apparent movement. Three body postures were ordered to produce a fluent (ABC) or a nonfluent (ACB) apparent movement. This enabled us to identify brain areas inv...

  20. Constructing Visual Perception of Body Movement with the Motor Cortex

    OpenAIRE

    Orgs, Guido; Dovern, Anna; Hagura, Nobuhiro; Haggard, Patrick; Fink, Gereon R.; Weiss, Peter H.

    2016-01-01

    The human brain readily perceives fluent movement from static input. Using functional magnetic resonance imaging, we investigated brain mechanisms that mediate fluent apparent biological motion (ABM) perception from sequences of body postures. We presented body and nonbody stimuli varying in objective sequence duration and fluency of apparent movement. Three body postures were ordered to produce a fluent (ABC) or a nonfluent (ACB) apparent movement. This enabled us to identify brain areas inv...

  1. Sensorimotor cortex injury effects on recovery of contralesional dexterous movements in Macaca mulatta.

    Science.gov (United States)

    Darling, Warren G; Pizzimenti, Marc A; Rotella, Diane L; Hynes, Stephanie M; Ge, Jizhi; Stilwell-Morecraft, Kimberly; Morecraft, Robert J

    2016-07-01

    The effects of primary somatosensory cortex (S1) injury on recovery of contralateral upper limb reaching and grasping were studied by comparing the consequences of isolated lesions to the arm/hand region of primary motor cortex (M1) and lateral premotor cortex (LPMC) to lesions of these same areas plus anterior parietal cortex (S1 and rostral area PE). We used multiple linear regression to assess the effects of gray and white matter lesion volumes on deficits in reaching and fine motor performance during the first month after the lesion, and during recovery of function over 3, 6 and 12months post-injury in 13 monkeys. Subjects with frontoparietal lesions exhibited larger deficits and poorer recovery as predicted, including one subject with extensive peri-Rolandic injury developing learned nonuse after showing signs of recovery. Regression analyses showed that total white matter lesion volume was strongly associated with initial post-lesion deficits in motor performance and with recovery of skill in reaching and manipulation. Multiple regression analyses using percent damage to caudal M1 (M1c), rostral S1 (S1r), LPMC and area PE as predictor variables showed that S1r lesion volumes were closely related to delayed post-lesion recovery of upper limb function, as well as lower skill level of recovery. In contrast, M1c lesion volume was related primarily to initial post-lesion deficits in hand motor performance. Overall, these findings demonstrate that frontoparietal injury impairs hand motor function more so than frontal motor injury alone, and results in slower and poorer recovery than lesions limited to frontal motor cortex. PMID:27091225

  2. Distributed Fading Memory for Stimulus Properties in the Primary Visual Cortex

    OpenAIRE

    Nikolić, Danko; Häusler, Stefan; Singer, Wolf; Maass, Wolfgang

    2009-01-01

    It is currently not known how distributed neuronal responses in early visual areas carry stimulus-related information. We made multielectrode recordings from cat primary visual cortex and applied methods from machine learning in order to analyze the temporal evolution of stimulus-related information in the spiking activity of large ensembles of around 100 neurons. We used sequences of up to three different visual stimuli (letters of the alphabet) presented for 100 ms and with intervals of 100...

  3. Distributed fading memory for stimulus properties in the primary visual cortex.

    OpenAIRE

    Danko Nikolić; Stefan Häusler; Wolf Singer; Wolfgang Maass

    2009-01-01

    It is currently not known how distributed neuronal responses in early visual areas carry stimulus-related information. We made multielectrode recordings from cat primary visual cortex and applied methods from machine learning in order to analyze the temporal evolution of stimulus-related information in the spiking activity of large ensembles of around 100 neurons. We used sequences of up to three different visual stimuli (letters of the alphabet) presented for 100 ms and with intervals of 100...

  4. Experimental cochlear hydrops in cats.

    Science.gov (United States)

    Eby, T L

    1986-11-01

    An experimental model of cochlear hydrops was created in cats. Ten cats underwent surgical procedures to obliterate the saccule, and their temporal bones were studied by light microscopy after sacrifice at 10 weeks. In one group the saccules were destroyed by maceration and aspiration. However, in these ears the saccular lumens were not obliterated and endolymphatic hydrops did not develop. Obliteration of the saccules was achieved in the second group after fascia was introduced into the area of the injured saccules. Cochlear endolymphatic hydrops was a consistent finding in these ears except when a fistula of the membranous labyrinth was present. However, in addition to fibrosis and new bone formation in the vestibules there were also degenerative changes in the hair cells, tectorial membranes, and striae vasculares of these cochleae. The results supported the longitudinal flow theory of endolymph and are consistent with the reported examples of cochlear endolymphatic hydrops in man. PMID:3812642

  5. Neural correlates of ankle movements during different motor tasks: A feasibility study.

    Science.gov (United States)

    Iandolo, R; Marre, I; Bellini, A; Bommarito, G; Oesingmann, N; Fleysher, L; Levrero, F; Mancardi, G; Casadio, M; Inglese, M

    2015-08-01

    This ongoing study investigates the neural correlates of ankle dorsi-plantar flexion in active, passive, and proprioceptive tasks. Specifically, we investigated two proprioceptive matching tasks that required a simple combination of active and passive ankle movements: (1) a memory-based ipsilateral matching task and (2) a contralateral concurrent matching task. As expected, during the passive tasks, subjects recruited the same brain areas involved in the correspondent active movements (primary motor cortex (M1), premotor cortex (PM) supplementary motor cortex (SMA) and primary somatosensory cortex (S1)), but the activations were lower. Instead, in both the proprioceptive matching tasks, subjects recruited more motor and sensory-motor areas of the brain and the activations were greater. PMID:26737338

  6. Reach task-associated excitatory overdrive of motor cortical neurons following infusion with ALS-CSF.

    Science.gov (United States)

    Sankaranarayani, R; Raghavan, Mohan; Nalini, A; Laxmi, T R; Raju, T R

    2014-01-01

    Converging evidence from transgenic animal models of amyotrophic lateral sclerosis (ALS) and human studies suggest alterations in excitability of the motor neurons in ALS. Specifically, in studies on human subjects with ALS the motor cortex was reported to be hyperexcitable. The present study was designed to test the hypothesis that infusion of cerebrospinal fluid from patients with sporadic ALS (ALS-CSF) into the rat brain ventricle can induce hyperexcitability and structural changes in the motor cortex leading to motor dysfunction. A robust model of sporadic ALS was developed experimentally by infusing ALS-CSF into the rat ventricle. The effects of ALS-CSF at the single neuron level were examined by recording extracellular single unit activity from the motor cortex while rats were performing a reach to grasp task. We observed an increase in the firing rate of the neurons of the motor cortex in rats infused with ALS-CSF compared to control groups. This was associated with impairment in a specific component of reach with alterations in the morphological characteristics of the motor cortex. It is likely that the increased cortical excitability observed in the present study could be the result of changes in the intrinsic properties of motor cortical neurons, a dysfunctional inhibitory mechanism and/or an underlying structural change culminating in a behavioral deficit. PMID:23900732

  7. Ototoxicity in dogs and cats

    OpenAIRE

    Oishi, Naoki; Talaska, Andra E.; Schacht, Jochen

    2012-01-01

    A variety of drugs in veterinary use have side effects that can potentially damage the senses of hearing or balance in animals. A large body of literature exists on the incidence and mechanisms of “ototoxicity” in experimental animals and in humans, but little is documented in domestic dogs and cats. However, the generality of these adverse actions across species allows us to extrapolate and provide the veterinarian with insight into possible complications of chemotherapy.

  8. Cat scratch disease in Greece

    OpenAIRE

    Karpathios, T; Golphinos, C; Psychou, P; Garoufi, A; Papadimitriou, A; Nicolaidou, P

    1998-01-01

    An indirect fluorescent antibody test for Bartonella henselae, B quintana, and B elizabethae was performed in all 18 children who presented to our paediatric outpatient clinic with cat scratch disease over a six year period. Serum samples were taken on admission, after 15 days, and after six months. Diagnosis was confirmed in 15 patients (83%) and was based on seroconversion or a fourfold change of the antibody titre to B henselae in 12 patients and on a single high titre...

  9. Temporomandibular ankylosis in the cat

    International Nuclear Information System (INIS)

    Ankylosis of the temporomandibular joint (TMJ) in the cat is an unusual complication of traumatic lesions involving articular (true ankylosis) or periarticular structures (false ankylosis). Seven cats with true ankylosis of the TMJ (four cases unilateral and three cases bilateral), of which previous trauma had been documented in five cases, were referred to the authors' clinic between September 1991 and October 1996. Radiographic assessment was performed in all cases, using dorsoventral and oblique projections. Five subjects underwent arthroplastic excision of the TMJ and, in the remaining two cases, stretching of the jaws was performed under general anaesthesia. The surgical outcome was satisfactory in all but one case, where partially decreased joint mobility was observed (follow-up time one to five years), but in the two cases where non-surgical treatment was carried out, recurrence of TMJ ankylosis was observed (follow-up time two to five months). In the authors' experience, surgery represents the treatment of choice for TMJ ankylosis in cats. Additional mandibular symphysiotomy can confirm the radiological findings in unilateral cases

  10. Schroedinger's Cat is not Alone

    CERN Document Server

    Gato, Beatriz

    2010-01-01

    We introduce the `Complete Wave Function' and deduce that all living beings, not just Schroedinger's cat, are actually described by a superposition of `alive' and `dead' quantum states; otherwise they would never die. Therefore this proposal provides a quantum mechanical explanation to the world-wide observation that we all pass away. Next we consider the Measurement problem in the framework of M-theory. For this purpose, together with Schroedinger's cat we also place inside the box Rasputin's cat, which is unaffected by poisson. We analyse the system identifying its excitations (catons and catinos) and we discuss its evolution: either to a classical fight or to a quantum entanglement. We also propose the $BSV\\Psi$ scenario, which implements the Complete Wave Function as well as the Big Bang and the String Landscape in a very (super)natural way. Then we test the gravitational decoherence of the entangled system applying an experimental setting due to Galileo. We also discuss the Information Loss paradox. For ...

  11. Direct transmission of the cat flea (Ctenocephalides felis) between cats exhibiting social behaviour

    OpenAIRE

    Franc, Michel; Bouhsira, Émilie; Beugnet, Frédéric

    2013-01-01

    A study design was created to assess the potential for fleas to infest cats directly from other cats. In the first experiment, six cats were infested with 100 fleas each and then immediately put in contact with six flea-free cats for 24 h. After removal of all fleas the study was repeated and the contact between cats lasted 48 h. The total numbers of fleas recovered out of the 600 fleas deposited on the 6 donor cats after each infestation were 499 and 486 at 24 h and 48 h respectively. At 1 h...

  12. Radioactive iodine therapy in cats with hyperthyroidism

    International Nuclear Information System (INIS)

    Eleven cats with hyperthyroidism were treated with radioactive iodine (131I). Previous unsuccessful treatments for hyperthyroidism included hemithyroidectomy (2 cats) and an antithyroid drug (7 cats). Two cats had no prior treatment. Thyroid scans, using technetium 99m, showed enlargement and increased radionuclide accumulation in 1 thyroid lobe in 5 cats and in both lobes in 6 cats. Serum thyroxine concentrations were high and ranged from 4.7 to 18 micrograms/dl. Radioactive iodine tracer studies were used to determine peak radioactive iodine uptake (RAIU) and effective and biological half-lives. Activity of 131I administered was calculated from peak RAIU, effective half-life, and estimated thyroid gland weight. Activity of 131I administered ranged from 1.0 to 5.9 mCi. The treatment goal was to deliver 20,000 rad to hyperactive thyroid tissue. However, retrospective calculations based on peak RAIU and effective half-life obtained during the treatment period showed that radiation doses actually ranged from 7,100 to 64,900 rad. Complete ablation of the hyperfunctioning thyroid tissue and a return to euthyroidism were seen in 7 cats. Partial responses were seen in 2 cats, and 2 cats became hypothyroid. It was concluded that 131I ablation of thyroid tumors was a reasonable alternative in the treatment of hyperthyroidism in cats. The optimal method of dosimetry remains to be determined

  13. Radioactive iodine therapy in cats with hyperthyroidism

    Energy Technology Data Exchange (ETDEWEB)

    Turrel, J.M.; Feldman, E.C.; Hays, M.; Hornof, W.J.

    1984-03-01

    Eleven cats with hyperthyroidism were treated with radioactive iodine (/sup 131/I). Previous unsuccessful treatments for hyperthyroidism included hemithyroidectomy (2 cats) and an antithyroid drug (7 cats). Two cats had no prior treatment. Thyroid scans, using technetium 99m, showed enlargement and increased radionuclide accumulation in 1 thyroid lobe in 5 cats and in both lobes in 6 cats. Serum thyroxine concentrations were high and ranged from 4.7 to 18 micrograms/dl. Radioactive iodine tracer studies were used to determine peak radioactive iodine uptake (RAIU) and effective and biological half-lives. Activity of /sup 131/I administered was calculated from peak RAIU, effective half-life, and estimated thyroid gland weight. Activity of /sup 131/I administered ranged from 1.0 to 5.9 mCi. The treatment goal was to deliver 20,000 rad to hyperactive thyroid tissue. However, retrospective calculations based on peak RAIU and effective half-life obtained during the treatment period showed that radiation doses actually ranged from 7,100 to 64,900 rad. Complete ablation of the hyperfunctioning thyroid tissue and a return to euthyroidism were seen in 7 cats. Partial responses were seen in 2 cats, and 2 cats became hypothyroid. It was concluded that /sup 131/I ablation of thyroid tumors was a reasonable alternative in the treatment of hyperthyroidism in cats. The optimal method of dosimetry remains to be determined.

  14. Acupuncture Enhances Effective Connectivity between Cerebellum and Primary Sensorimotor Cortex in Patients with Stable Recovery Stroke

    Directory of Open Access Journals (Sweden)

    Zijing Xie

    2014-01-01

    Full Text Available Recent neuroimaging studies have demonstrated that stimulation of acupuncture at motor-implicated acupoints modulates activities of brain areas relevant to the processing of motor functions. This study aims to investigate acupuncture-induced changes in effective connectivity among motor areas in hemiparetic stroke patients by using the multivariate Granger causal analysis. A total of 9 stable recovery stroke patients and 8 healthy controls were recruited and underwent three runs of fMRI scan: passive finger movements and resting state before and after manual acupuncture stimuli. Stroke patients showed significantly attenuated effective connectivity between cortical and subcortical areas during passive motor task, which indicates inefficient information transmissions between cortical and subcortical motor-related regions. Acupuncture at motor-implicated acupoints showed specific modulations of motor-related network in stroke patients relative to healthy control subjects. This specific modulation enhanced bidirectionally effective connectivity between the cerebellum and primary sensorimotor cortex in stroke patients, which may compensate for the attenuated effective connectivity between cortical and subcortical areas during passive motor task and, consequently, contribute to improvement of movement coordination and motor learning in subacute stroke patients. Our results suggested that further efficacy studies of acupuncture in motor recovery can focus on the improvement of movement coordination and motor learning during motor rehabilitation.

  15. Talking Hands: Tongue Motor Excitability During Observation of Hand Gestures Associated with Words.

    OpenAIRE

    Naeem Komeilipoor; Carmelo Mario Vicario

    2014-01-01

    Perception of speech and gestures engage common brain areas. Neural regions involved in speech perception overlap with those involved in speech production in an articulator-specific manner. Yet, it is unclear whether motor cortex also has a role in processing communicative actions like gesture and sign language. We asked whether the mere observation of hand gestures, paired and not paired with words, may result in changes in the excitability of the hand and tongue areas of motor cortex. Using...

  16. Talking hands: tongue motor excitability during observation of hand gestures associated with words

    OpenAIRE

    Komeilipoor, Naeem; Vicario, Carmelo Mario; Daffertshofer, Andreas; Cesari, Paola

    2014-01-01

    Perception of speech and gestures engage common brain areas. Neural regions involved in speech perception overlap with those involved in speech production in an articulator-specific manner. Yet, it is unclear whether motor cortex also has a role in processing communicative actions like gesture and sign language. We asked whether the mere observation of hand gestures, paired and not paired with words, may result in changes in the excitability of the hand and tongue areas of motor cortex. Using...

  17. Management of obesity in cats

    Directory of Open Access Journals (Sweden)

    Hoelmkjaer KM

    2014-09-01

    Full Text Available Kirsten M Hoelmkjaer, Charlotte R Bjornvad Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark Abstract: Obesity is a common nutritional disorder in cats, especially when they are neutered and middle-aged. Obesity predisposes cats to several metabolic and clinical disorders, including insulin resistance, diabetes mellitus, lameness, and skin disease. Prevention and treatment of obesity is therefore of great importance in veterinary practice. Correct assessment of body composition is important for recognizing early states of obesity and for monitoring success of weight-loss programs. Various methods for assessing body composition have been proposed, of which a 9-point body-condition score has been validated in cats, and is possibly the most simple to use in the clinic; however, for extremely obese individuals, it is less useful. When calculating the appropriate daily caloric intake for a weight-loss plan, the aim is to maintain a safe weight-loss rate, increasing the chance of preserving lean body mass and decreasing the risk of developing hepatic lipidosis, while also producing a sufficient weight-loss rate to keep owners motivated. A weight-loss rate of 0.5%–2% per week is recommended, which for a cat that needs to lose 3 kg body weight results in an anticipated time for reaching the target weight of 24–60 weeks. There are several purpose-made weight-loss diets available. The optimal composition of a weight-loss diet for cats is unknown, but most of the available products have lower caloric density, an increased nutrient:energy ratio, and higher protein and fiber content. Regular follow-up visits allow the caloric intake to be adjusted based on progress, and possibly increase the chance of success. This review discusses the risk factors for and consequences of obesity, and gives directions for formulating a weight-loss plan, including daily caloric

  18. Human Posterior Parietal Cortex Plans Where to Reach and What to Avoid

    OpenAIRE

    Lindner, Axel; Iyer, Asha; Kagan, Igor; Andersen, Richard A.

    2010-01-01

    In this time-resolved functional magnetic resonance imaging (fMRI) study, we aimed to trace the neuronal correlates of covert planning processes that precede visually guided motor behavior. Specifically, we asked whether human posterior parietal cortex has prospective planning activity that can be distinguished from activity related to retrospective visual memory and attention. Although various electrophysiological studies in monkeys have demonstrated such motor planning at the level of parie...

  19. Motor Magnates

    Institute of Scientific and Technical Information of China (English)

    ISABEL DING

    2008-01-01

    @@ The automotive industry is often seen as a man's world. Wang Fengying (王风英) begs to differ. The 38-year-old has presided over Great Wall Motors (长城汽车), the leading pick-up truck and Sport Utility Vehicle(SUV) manufacturer in China for the past five years.

  20. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    MOTOR is the first assignment that students at Unit 1a of the School of Architecture are introduced to. The purpose of the assignment is to shake up the students and their preconceptions of what architec- ture is. This is done by introducing them to a working method that al- lows them to develop...