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Excitability change in the primary motor cortex after resection of the supplementary motor area in humans
Abstracts / Neuroscience Research 71S (2011) e108–e415
P4-h07 Muscle fatigue-induced enhancement of corticomuscular coherence following sustained submaximal isometric contraction of the tibialis anterior muscle
Yoshihisa Masakado 1 , Junichi Ushiyama 2,3 , Masanori Katsu 3 , Akio Kimura 4 , Meigen Liu 2 , Junichi Ushiba 2,4,5 1
Department of Rehabilitation Medicine, Tokai University School of Medicine Department of Rehabilitation Medicine, Keio University School of Medicine 3 Graduate School of Fundamental Science and Technology, Keio University 4 Keio University Tsukigase Rehabilitation Center 5 Department of Biosciences and Informatics, Faculty of Science and Technology 2
Oscillatory activity of the sensorimotor cortex shows coherence with muscle activity within the 15–35 Hz frequency band (beta band) during weak to moderate sustained isometric contraction. We aimed to examine the acute changes in this corticomuscular coupling due to muscle fatigue and its effect on the steadiness of the exerted force. We quantified the coherence between electroencephalogram (EEG) recorded over the sensorimotor cortex and rectified surface electromyogram (EMG) of the tibialis anterior muscle (TA), and the coefficient of variance of the dorsiflexion force (ForceCV) and sum of the auto-power spectral density function of the force within band (Force beta PSD), during 30% of maximal voluntary contraction (MVC) for 60 s before (pre-fatiguing task) and after (post-fatiguing task) muscle fatigue induced by sustained isometric contraction at 50% of MVC until exhaustion in seven healthy male subjects. The magnitude of EEG–EMG coherence increased in post-fatiguing task in six out of seven subjects. The maximal peak of EEG–EMG coherence stayed within the beta band in both preand post-fatiguing tasks. Interestingly, two subjects, who had no significant EEG–EMG coherence in pre-fatiguing task, showed significant coherence in post-fatiguing task. Additionally, Force CV and Force beta PSD significantly increased after muscle fatigue. These data suggest that when muscle fatigue develops, the central nervous system enhances oscillatory muscular activity in the beta band stronger coupled with the sensorimotor cortex activity accomplishing the sustained isometric contraction at lower performance levels. Research fund: Grant-in-Aid for Young Scientists (B) (#21700594). doi:10.1016/j.neures.2011.07.1520
P4-h08 Differential distribution of activities reflecting planning, preparation, and execution of action in six motor areas of the frontal lobe Yoshihisa Nakayama 1,2 , Tomoko 1,2 Arimura , Jun Tanji 1,3 , Eiji Hoshi 1,2
Yamagata 1,2 , Nariko
1
Tamagawa University Brain Science Institute, Tokyo, Japan 2 Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan 3 Tohoku University Brain Science Center, Sendai, Japan The aim of this study was to reveal the functional specificity of multiple motor areas in the frontal lobe by comparing neuronal activity recorded from six motor areas of monkeys (Macaca fuscata) performing an identical visuomotor task (Nakayama, et al., J Neurosci, 2008). We recorded neuronal activity from the following areas: (1) the primary motor area (MI), (2) the rostral part and (3) the caudal part of the dorsal premotor area in area F2 (PMdr and PMdc, respectively), (4) the pre-dorsal premotor area (pre-PMd) in area F7, (5) the ventral premotor area (PMv), and (6) the caudal part of the cingulate motor area (CMAc). By applying a cluster analysis to the general activity increase and decrease along the task progress, we successfully classified the activity patterns into six groups, out of which five groups were considered to be involved in planning, preparing, and executing action. Neurons in Group 1 responded to the appearance of the cue instructing action at an abstract level, and neurons in Group 2 responded to the appearance of the choice cue that allowed the animal to determine the exact target of the forthcoming reaching movement. Neurons in Group 3 were active during action preparation. Neurons in Group 4 were active in initiating movements, whereas those in Group 5 were in touching targets. Neurons in Group 1 and 2, deemed to play a central role in action planning, were found mainly in pre-PMd, PMdr, and PMdc. Although Group 3 neurons with preparatory activity were found in the six areas, the movement direction selectivity was amply reflected in PMdc, PMv, and MI. Group 4 neurons that were active in movement initiation were mainly found in the PMv, CMAc, and MI, whereas Group 5 neurons were in the CMAc and MI. In Groups 4 and 5, although the movement direction selectivity was amply reflected in PMv and MI, it was much less in CMAc. These results provide further evidence that multiple areas in the frontal lobe play different roles in controlling action.
e347
Research fund: KAKENHI(22830086), KAKENHI(19670004), Takeda Science Foundation. doi:10.1016/j.neures.2011.07.1521
P4-h09 Excitability change in the primary motor cortex after resection of the supplementary motor area in humans Takefumi Hitomi 1 , Riki Matsumoto 2 , Tatsuhide Oga 2 , Nobuhiro Mikuni 3 , Susumu Miyamoto 3 , Hiroshi Shibasaki 1 , Ryosuke Takahashi 1 , Akio Ikeda 1 1 Dept. Respi Care and Sleep Cont Med, Dept. Neurology, Grad. Sch. of Med., Kyoto Univ., Kyoto, Japan 2 Dept. Neurology, Grad. Sch. of Med., Kyoto Univ., Kyoto, Japan 3 Dept. Neurosurgery, Grad. Sch. of Med., Kyoto Univ., Kyoto, Japan
Objectives: To investigate the pathophysiology of the supplementary motor area (SMA) syndrome by measuring the excitability in the primary motor cortex (MI) in patients after the SMA resection. Methods: Five patients (1 man and 4 women, age: 31 ± 9.3 years), underwent the SMA resection for brain tumor or intractable partial epilepsy, and were studied by single pulse transcranial magnetic stimulation (TMS). Two of them were also studied by paired pulse TMS. After the SMA resection, 4 patients (Patient 1, 2, 4 and 5) had transient mild hemiparesis and impairment in alternating bilateral hand movements and 1 patient (Patient 3) had moderate hemiparesis. These symptoms were predominant on the contralateral side to the SMA resection. Results: Single pulse TMS at MI showed increased motor threshold and decreased motor evoked potential (MEP) amplitude in 2 patients (Patient 1 and 3) on the affected side, but the other 3 patients (Patient 2, 4 and 5) showed no apparent abnormality. There was no significant difference in resting threshold, MEP latency or amplitude between the unaffected side (57 ± 10%, 21.6 ± 0.9 ms, 1.4 ± 1.4 mV) and those of the affected side (72 ± 12%, 20.5 ± 1.6 ms, 0.8 ± 0.3 mV) in 5 patients. Paired pulse TMS at MI showed loss of inhibition on the affected side during the interstimulus interval of 2 to 3 ms in Patient 1. The symptoms gradually improved and recovered completely within 1 month after the surgery, when the intracortical inhibition returned to normal. On the other hand, paired pulse TMS at MI showed normal in Patient 2. Conclusions: Decreased excitation or disinhibition at MI ipsilateral to the resected SMA in 2 patients (Patient 1 and 3), but there was no consistent relationship between the TMS findings and motor symptoms. It is most likely that motor symptom of the SMA syndrome is mainly caused by the functional change of the SMA itself, but not by that of the MI. doi:10.1016/j.neures.2011.07.1522
P4-h10 Directional tuning of cortical activity estimated by vbmeg during wrist movements Kenji Ogawa 1,2 , Masa-aki Sato 3 , Hiroshi Imamizu 1,4 1
ATR Cognitive Mechanisms Laboratories, Kyoto, Japan 2 JSPS, Tokyo, Japan ATR Neural Information Analysis Laboratories, Kyoto, Japan 4 NICT Brain ICT Lab, Kyoto, Japan
3
Our recent studies have successfully reconstructed wrist movements using cortical currents analyzed by hierarchical variational bayesian method (vbmeg), which combines MEG and fMRI activities and estimates cortical currents on the order of millimeters and milliseconds. However, the neural underpinning of the reconstruction is rather unclear. We tested whether the estimated currents of individual vertex show directional selectivity, which has been intensively studied in neurophysiology with non-human primates. In the experiment, participants performed visually guided wrist movement toward eight different target positions in the MEG scanner. Results showed a broad directional tuning in individual vertex of the parieto-frontal regions, which showed maximal response to preferred direction (PD) and decreased response as the angular distance between PD and movement direction increased. Using a conventional population vector method, movement direction could be successfully reconstructed during execution as well as preparatory period before movement initiation. To dissociate extrinsic and intrinsic coordinates in visuomotor transformation, subjects then rotated their wrist in 90 degree and performed the same task. The reconstructed direction was largely congruent with extrinsic coordinates irrespective of wrist rotation, whereas we could also find intrinsic coordinates for a selected region around the primary motor cortex. Taken together, a broad directional tuning was found for individual vertex in cortical activity estimated
P4-h07 Muscle fatigue-induced enhancement of corticomuscular coherence following sustained submaximal isometric contraction of the tibialis anterior muscle
Yoshihisa Masakado 1 , Junichi Ushiyama 2,3 , Masanori Katsu 3 , Akio Kimura 4 , Meigen Liu 2 , Junichi Ushiba 2,4,5 1
Department of Rehabilitation Medicine, Tokai University School of Medicine Department of Rehabilitation Medicine, Keio University School of Medicine 3 Graduate School of Fundamental Science and Technology, Keio University 4 Keio University Tsukigase Rehabilitation Center 5 Department of Biosciences and Informatics, Faculty of Science and Technology 2
Oscillatory activity of the sensorimotor cortex shows coherence with muscle activity within the 15–35 Hz frequency band (beta band) during weak to moderate sustained isometric contraction. We aimed to examine the acute changes in this corticomuscular coupling due to muscle fatigue and its effect on the steadiness of the exerted force. We quantified the coherence between electroencephalogram (EEG) recorded over the sensorimotor cortex and rectified surface electromyogram (EMG) of the tibialis anterior muscle (TA), and the coefficient of variance of the dorsiflexion force (ForceCV) and sum of the auto-power spectral density function of the force within band (Force beta PSD), during 30% of maximal voluntary contraction (MVC) for 60 s before (pre-fatiguing task) and after (post-fatiguing task) muscle fatigue induced by sustained isometric contraction at 50% of MVC until exhaustion in seven healthy male subjects. The magnitude of EEG–EMG coherence increased in post-fatiguing task in six out of seven subjects. The maximal peak of EEG–EMG coherence stayed within the beta band in both preand post-fatiguing tasks. Interestingly, two subjects, who had no significant EEG–EMG coherence in pre-fatiguing task, showed significant coherence in post-fatiguing task. Additionally, Force CV and Force beta PSD significantly increased after muscle fatigue. These data suggest that when muscle fatigue develops, the central nervous system enhances oscillatory muscular activity in the beta band stronger coupled with the sensorimotor cortex activity accomplishing the sustained isometric contraction at lower performance levels. Research fund: Grant-in-Aid for Young Scientists (B) (#21700594). doi:10.1016/j.neures.2011.07.1520
P4-h08 Differential distribution of activities reflecting planning, preparation, and execution of action in six motor areas of the frontal lobe Yoshihisa Nakayama 1,2 , Tomoko 1,2 Arimura , Jun Tanji 1,3 , Eiji Hoshi 1,2
Yamagata 1,2 , Nariko
1
Tamagawa University Brain Science Institute, Tokyo, Japan 2 Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan 3 Tohoku University Brain Science Center, Sendai, Japan The aim of this study was to reveal the functional specificity of multiple motor areas in the frontal lobe by comparing neuronal activity recorded from six motor areas of monkeys (Macaca fuscata) performing an identical visuomotor task (Nakayama, et al., J Neurosci, 2008). We recorded neuronal activity from the following areas: (1) the primary motor area (MI), (2) the rostral part and (3) the caudal part of the dorsal premotor area in area F2 (PMdr and PMdc, respectively), (4) the pre-dorsal premotor area (pre-PMd) in area F7, (5) the ventral premotor area (PMv), and (6) the caudal part of the cingulate motor area (CMAc). By applying a cluster analysis to the general activity increase and decrease along the task progress, we successfully classified the activity patterns into six groups, out of which five groups were considered to be involved in planning, preparing, and executing action. Neurons in Group 1 responded to the appearance of the cue instructing action at an abstract level, and neurons in Group 2 responded to the appearance of the choice cue that allowed the animal to determine the exact target of the forthcoming reaching movement. Neurons in Group 3 were active during action preparation. Neurons in Group 4 were active in initiating movements, whereas those in Group 5 were in touching targets. Neurons in Group 1 and 2, deemed to play a central role in action planning, were found mainly in pre-PMd, PMdr, and PMdc. Although Group 3 neurons with preparatory activity were found in the six areas, the movement direction selectivity was amply reflected in PMdc, PMv, and MI. Group 4 neurons that were active in movement initiation were mainly found in the PMv, CMAc, and MI, whereas Group 5 neurons were in the CMAc and MI. In Groups 4 and 5, although the movement direction selectivity was amply reflected in PMv and MI, it was much less in CMAc. These results provide further evidence that multiple areas in the frontal lobe play different roles in controlling action.
e347
Research fund: KAKENHI(22830086), KAKENHI(19670004), Takeda Science Foundation. doi:10.1016/j.neures.2011.07.1521
P4-h09 Excitability change in the primary motor cortex after resection of the supplementary motor area in humans Takefumi Hitomi 1 , Riki Matsumoto 2 , Tatsuhide Oga 2 , Nobuhiro Mikuni 3 , Susumu Miyamoto 3 , Hiroshi Shibasaki 1 , Ryosuke Takahashi 1 , Akio Ikeda 1 1 Dept. Respi Care and Sleep Cont Med, Dept. Neurology, Grad. Sch. of Med., Kyoto Univ., Kyoto, Japan 2 Dept. Neurology, Grad. Sch. of Med., Kyoto Univ., Kyoto, Japan 3 Dept. Neurosurgery, Grad. Sch. of Med., Kyoto Univ., Kyoto, Japan
Objectives: To investigate the pathophysiology of the supplementary motor area (SMA) syndrome by measuring the excitability in the primary motor cortex (MI) in patients after the SMA resection. Methods: Five patients (1 man and 4 women, age: 31 ± 9.3 years), underwent the SMA resection for brain tumor or intractable partial epilepsy, and were studied by single pulse transcranial magnetic stimulation (TMS). Two of them were also studied by paired pulse TMS. After the SMA resection, 4 patients (Patient 1, 2, 4 and 5) had transient mild hemiparesis and impairment in alternating bilateral hand movements and 1 patient (Patient 3) had moderate hemiparesis. These symptoms were predominant on the contralateral side to the SMA resection. Results: Single pulse TMS at MI showed increased motor threshold and decreased motor evoked potential (MEP) amplitude in 2 patients (Patient 1 and 3) on the affected side, but the other 3 patients (Patient 2, 4 and 5) showed no apparent abnormality. There was no significant difference in resting threshold, MEP latency or amplitude between the unaffected side (57 ± 10%, 21.6 ± 0.9 ms, 1.4 ± 1.4 mV) and those of the affected side (72 ± 12%, 20.5 ± 1.6 ms, 0.8 ± 0.3 mV) in 5 patients. Paired pulse TMS at MI showed loss of inhibition on the affected side during the interstimulus interval of 2 to 3 ms in Patient 1. The symptoms gradually improved and recovered completely within 1 month after the surgery, when the intracortical inhibition returned to normal. On the other hand, paired pulse TMS at MI showed normal in Patient 2. Conclusions: Decreased excitation or disinhibition at MI ipsilateral to the resected SMA in 2 patients (Patient 1 and 3), but there was no consistent relationship between the TMS findings and motor symptoms. It is most likely that motor symptom of the SMA syndrome is mainly caused by the functional change of the SMA itself, but not by that of the MI. doi:10.1016/j.neures.2011.07.1522
P4-h10 Directional tuning of cortical activity estimated by vbmeg during wrist movements Kenji Ogawa 1,2 , Masa-aki Sato 3 , Hiroshi Imamizu 1,4 1
ATR Cognitive Mechanisms Laboratories, Kyoto, Japan 2 JSPS, Tokyo, Japan ATR Neural Information Analysis Laboratories, Kyoto, Japan 4 NICT Brain ICT Lab, Kyoto, Japan
3
Our recent studies have successfully reconstructed wrist movements using cortical currents analyzed by hierarchical variational bayesian method (vbmeg), which combines MEG and fMRI activities and estimates cortical currents on the order of millimeters and milliseconds. However, the neural underpinning of the reconstruction is rather unclear. We tested whether the estimated currents of individual vertex show directional selectivity, which has been intensively studied in neurophysiology with non-human primates. In the experiment, participants performed visually guided wrist movement toward eight different target positions in the MEG scanner. Results showed a broad directional tuning in individual vertex of the parieto-frontal regions, which showed maximal response to preferred direction (PD) and decreased response as the angular distance between PD and movement direction increased. Using a conventional population vector method, movement direction could be successfully reconstructed during execution as well as preparatory period before movement initiation. To dissociate extrinsic and intrinsic coordinates in visuomotor transformation, subjects then rotated their wrist in 90 degree and performed the same task. The reconstructed direction was largely congruent with extrinsic coordinates irrespective of wrist rotation, whereas we could also find intrinsic coordinates for a selected region around the primary motor cortex. Taken together, a broad directional tuning was found for individual vertex in cortical activity estimated