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Local excitatory network in rat prepositus hypoglossi nucleus
Abstracts P2-g15 Motor imagery in mental rotation of hand pictures Kotaro Takeda 1,2 , Nobuaki Shimoda 1,2 , Hiroyuki Kato 1,2 1
Intl. University of Hlth. and Welfare Hosp., Nasushiobara, Japan; JST, Kawaguchi, Japan
2
CREST,
Mental rotation of hand picture is considered to cause motor imagery. Sixteen righthanders were recruited and the times to make left-right judgments for a rotated hand picture were compared among picture orientations. We also used near-infrared spectroscopy to examine the activations in the premotor, sensorimotor, and parietal association cortices of five right-handed subjects during mental rotation using hand pictures. A rotated hand picture for a task period (8 pictures/cycle) and an arrow picture (point to right or left) for a resting period (8 pictures/cycle) were presented every 2 s (total 6 cycles). The subjects were required to make left–right judgments of the hand or arrow direction. The subjects recognized a right hand faster than a left hand in counterclockwise orientation, and recognized a left hand faster than a right hand in clockwise orientation. Significant [Oxy-Hb] increases were observed in the bilateral motor related areas. These findings suggest that right-handers make left–right judgments by mentally rotating their own hand to an orientation of presented hand picture. doi:10.1016/j.neures.2009.09.882
S169
P2-g18 Reconstruction of wrist-movement trajectories using magnetoencephalography-source currents estimated by a hierarchical Bayesian method Hiroshi Imamizu 1,2 , Akihiro Toda 2,3 , Mitsuo Kawato 2 , Masa-aki Sato 2 1
NICT Bio-ICT Group, Kyoto, Japan; 2 ATR Computational Neurosci. Labs., Kyoto, Japan; 3 Nagaoka University of Technology, Nagaoka, Japan
We reconstructed the trajectories of the index fingertip by using a time series of magnetoencephalography (MEG)-source currents obtained during pointing movements in various directions. We incorporated fMRI activity as a hierarchical prior and used a hierarchical Bayesian method to estimate the cortical-source currents from the MEG-sensor data. Then, we estimated a linear model that predicts the fingertip position by using a weighted sum of time series from the estimated source currents in the training datasets. For the estimation, we used a sparse-linear-regression method to determine an appropriate set of weights. The method showed good generalization (reconstruction) performance for the test datasets: the mean error between the predicted and actual positions was 1.5 cm, and the mean coefficient of determination was 0.7. Thus, our proposed method provides an effective approach for reconstruction of movement trajectory by using noninvasive brain activity. doi:10.1016/j.neures.2009.09.885
P2-g16 Functional differences between dominant and non-dominant lower limbs in compensatory stepping Kei Takakura, Sayaka Fujiwara, Takashi Yamaguchi Grad. Sch. Sci. & Engin., Yamagata University, Yamagata, Japan
P2-g19 Spike synchrony modulated by membrane properties in a network model of globus pallidus externus Tomohiro Fujita, Katsunori Kitano
To understand functional differences between dominant and non-dominant limbs in compensatory stepping, we analyzed electromyographic (EMG) activities of ankle and knee joint muscles of both limbs and postural responses while subjects stepped forward with the dominant or non-dominant limb. EMG activities and postures before stepping with dominant or non-dominant limb were compared with standing still. Differences of EMG activities and trajectories of stepping between stepping with dominant and non-dominant limbs were also examined. In standing posture before stepping, EMG activity patterns were similar among three conditions. The posture before stepping with the dominant limb was like one in standing still. In stepping motion, swing trajectories of the dominant limb showed a lower level of the peak height than those of the non-dominant limb, suggesting that stepping with dominant limb was well practiced. It was supposed that in upright standing the nondominant limb mainly supported a body, while the dominant limb was prepared for actions like compensatory stepping.
Subthalamic nuclei (STN) and globus pallidus externus (GPe) are important nuclei for basal ganglia functions as shown in normal/pathological neural activities of the indirect pathway. Dynamical properties of the GPe network may be closely related to pathological rhythmical burst activity of the indirect pathway. We here investigated how spike synchrony of a model of the GPe network was altered by membrane property modulations. To achieve such purposes, we applied the phase response analysis to a model GPe neuron and conducted model simulations of a GPe network, changing gating mechanism of a persistent sodium channel and L-type calcium channel, which are modulated by dopamine in STN neurons and striatal spiny neurons. The gating mechanism modulation that activates L-type calcium channel induced the synchronous activity. The results suggested the dopaminergic effect on the intrinsic membrane property was one of the candidates to induce pathological burst activity in the STN.
doi:10.1016/j.neures.2009.09.883
doi:10.1016/j.neures.2009.09.886
P2-g17 The effect of transcranial magnetic stimulation over the dorsolateral prefrontal cortex on the inhibition of stereotyped responses during a rock-paper-scissors task Hiroshi Kadota 1,2 , Hirofumi Sekiguchi 2,3 , Shigeki Takeuchi 2 , Makoto Miyazaki 2,4 , Yutaka Kohno 2,5 , Yasoichi Nakajima 2
P2-g20 Local excitatory network in rat prepositus hypoglossi nucleus Yasuhiko Saito, Masato Shino, Yuchio Yanagawa
1
2
Course of Functional Control Systems, SIT, Saitama, Japan; Dept of Rehab for Sensory Functions, Res Inst of NRCD, Tokorozawa, Japan; 3 Sports, Coaching, Training Course, Jobu Univ, Gunma, Japan; 4 WIAS, Waseda Univ, Tokyo, Japan; 5 Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan Clinical and neuropsychological studies showed that during a modified rock-paperscissors (RPS) task, trying to lose against a presented gesture is related to the inhibition of habitual responses. Our previous study by using functional MRI suggests that the left dorsolateral prefrontal cortex (DLPFC) may be involved in the inhibition of stereotyped responses (Kadota et al., 2007). In the present study, we applied TMS to the left DLPFC during a modified RPS task. When TMS was given, subjects tended to win unintentionally although subjects were required to lose. This result reinforces the notion that the left DLPFC plays an important role in the inhibition of habitual responses. Reference Kadota, et al., 2007. Neurosci Res Suppl. doi:10.1016/j.neures.2009.09.884
Grad Sch Sci Eng, Ritsumeikan University, Japan
Dept Genetic and Behavioral Neurosci, Gunma Univ Grad School of Medcine, Japan To clarify the structure of excitatory networks in the prepositus hypoglossi nucleus (PHN) that is involved in velocity-position integration for horizontal eye movements, we investigated synaptic responses of PHN neurons by whole-cell voltage-clamp recordings in rat brainstem slices. In the presence of 100 M picrotoxin and 20 M strychnine, application of burst stimulation (10–30 A, 100 Hz, 20 pulses) to a nearby site of a recorded PHN neuron induced large inward currents and increased the rate of spontaneous inward currents. Even when the PHN was separated from the brainstem slice, the burst stimulation induced the inward currents in PHN neurons in the isolated PHN. The inward currents decreased to about the half by 50 M APV and the residual currents were mostly abolished by a blocker of Ca2+-permeiable AMPA receptor, Naspm (100 M). These results suggest that the inward currents were induced by activation of the local excitatory network in the PHN and Ca2+permeiable AMPA receptor contribute to activation of the network. doi:10.1016/j.neures.2009.09.887
P2-g21 Spatial distribution of simple-spike response of Purkinje cells in the cerebellar nodulus and uvula during vertical head rotation Kenichi Ozawa 1,2 , Toshihiro Kitama 1 , Yu Sato 3 1 Center for Life Science Research, University of Yamanashi, Yamanashi, Japan; 2 Department of Occupational Therapy, Health Science University, Yamanashi, Japan; 3 Department of Physiology, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
Intl. University of Hlth. and Welfare Hosp., Nasushiobara, Japan; JST, Kawaguchi, Japan
2
CREST,
Mental rotation of hand picture is considered to cause motor imagery. Sixteen righthanders were recruited and the times to make left-right judgments for a rotated hand picture were compared among picture orientations. We also used near-infrared spectroscopy to examine the activations in the premotor, sensorimotor, and parietal association cortices of five right-handed subjects during mental rotation using hand pictures. A rotated hand picture for a task period (8 pictures/cycle) and an arrow picture (point to right or left) for a resting period (8 pictures/cycle) were presented every 2 s (total 6 cycles). The subjects were required to make left–right judgments of the hand or arrow direction. The subjects recognized a right hand faster than a left hand in counterclockwise orientation, and recognized a left hand faster than a right hand in clockwise orientation. Significant [Oxy-Hb] increases were observed in the bilateral motor related areas. These findings suggest that right-handers make left–right judgments by mentally rotating their own hand to an orientation of presented hand picture. doi:10.1016/j.neures.2009.09.882
S169
P2-g18 Reconstruction of wrist-movement trajectories using magnetoencephalography-source currents estimated by a hierarchical Bayesian method Hiroshi Imamizu 1,2 , Akihiro Toda 2,3 , Mitsuo Kawato 2 , Masa-aki Sato 2 1
NICT Bio-ICT Group, Kyoto, Japan; 2 ATR Computational Neurosci. Labs., Kyoto, Japan; 3 Nagaoka University of Technology, Nagaoka, Japan
We reconstructed the trajectories of the index fingertip by using a time series of magnetoencephalography (MEG)-source currents obtained during pointing movements in various directions. We incorporated fMRI activity as a hierarchical prior and used a hierarchical Bayesian method to estimate the cortical-source currents from the MEG-sensor data. Then, we estimated a linear model that predicts the fingertip position by using a weighted sum of time series from the estimated source currents in the training datasets. For the estimation, we used a sparse-linear-regression method to determine an appropriate set of weights. The method showed good generalization (reconstruction) performance for the test datasets: the mean error between the predicted and actual positions was 1.5 cm, and the mean coefficient of determination was 0.7. Thus, our proposed method provides an effective approach for reconstruction of movement trajectory by using noninvasive brain activity. doi:10.1016/j.neures.2009.09.885
P2-g16 Functional differences between dominant and non-dominant lower limbs in compensatory stepping Kei Takakura, Sayaka Fujiwara, Takashi Yamaguchi Grad. Sch. Sci. & Engin., Yamagata University, Yamagata, Japan
P2-g19 Spike synchrony modulated by membrane properties in a network model of globus pallidus externus Tomohiro Fujita, Katsunori Kitano
To understand functional differences between dominant and non-dominant limbs in compensatory stepping, we analyzed electromyographic (EMG) activities of ankle and knee joint muscles of both limbs and postural responses while subjects stepped forward with the dominant or non-dominant limb. EMG activities and postures before stepping with dominant or non-dominant limb were compared with standing still. Differences of EMG activities and trajectories of stepping between stepping with dominant and non-dominant limbs were also examined. In standing posture before stepping, EMG activity patterns were similar among three conditions. The posture before stepping with the dominant limb was like one in standing still. In stepping motion, swing trajectories of the dominant limb showed a lower level of the peak height than those of the non-dominant limb, suggesting that stepping with dominant limb was well practiced. It was supposed that in upright standing the nondominant limb mainly supported a body, while the dominant limb was prepared for actions like compensatory stepping.
Subthalamic nuclei (STN) and globus pallidus externus (GPe) are important nuclei for basal ganglia functions as shown in normal/pathological neural activities of the indirect pathway. Dynamical properties of the GPe network may be closely related to pathological rhythmical burst activity of the indirect pathway. We here investigated how spike synchrony of a model of the GPe network was altered by membrane property modulations. To achieve such purposes, we applied the phase response analysis to a model GPe neuron and conducted model simulations of a GPe network, changing gating mechanism of a persistent sodium channel and L-type calcium channel, which are modulated by dopamine in STN neurons and striatal spiny neurons. The gating mechanism modulation that activates L-type calcium channel induced the synchronous activity. The results suggested the dopaminergic effect on the intrinsic membrane property was one of the candidates to induce pathological burst activity in the STN.
doi:10.1016/j.neures.2009.09.883
doi:10.1016/j.neures.2009.09.886
P2-g17 The effect of transcranial magnetic stimulation over the dorsolateral prefrontal cortex on the inhibition of stereotyped responses during a rock-paper-scissors task Hiroshi Kadota 1,2 , Hirofumi Sekiguchi 2,3 , Shigeki Takeuchi 2 , Makoto Miyazaki 2,4 , Yutaka Kohno 2,5 , Yasoichi Nakajima 2
P2-g20 Local excitatory network in rat prepositus hypoglossi nucleus Yasuhiko Saito, Masato Shino, Yuchio Yanagawa
1
2
Course of Functional Control Systems, SIT, Saitama, Japan; Dept of Rehab for Sensory Functions, Res Inst of NRCD, Tokorozawa, Japan; 3 Sports, Coaching, Training Course, Jobu Univ, Gunma, Japan; 4 WIAS, Waseda Univ, Tokyo, Japan; 5 Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan Clinical and neuropsychological studies showed that during a modified rock-paperscissors (RPS) task, trying to lose against a presented gesture is related to the inhibition of habitual responses. Our previous study by using functional MRI suggests that the left dorsolateral prefrontal cortex (DLPFC) may be involved in the inhibition of stereotyped responses (Kadota et al., 2007). In the present study, we applied TMS to the left DLPFC during a modified RPS task. When TMS was given, subjects tended to win unintentionally although subjects were required to lose. This result reinforces the notion that the left DLPFC plays an important role in the inhibition of habitual responses. Reference Kadota, et al., 2007. Neurosci Res Suppl. doi:10.1016/j.neures.2009.09.884
Grad Sch Sci Eng, Ritsumeikan University, Japan
Dept Genetic and Behavioral Neurosci, Gunma Univ Grad School of Medcine, Japan To clarify the structure of excitatory networks in the prepositus hypoglossi nucleus (PHN) that is involved in velocity-position integration for horizontal eye movements, we investigated synaptic responses of PHN neurons by whole-cell voltage-clamp recordings in rat brainstem slices. In the presence of 100 M picrotoxin and 20 M strychnine, application of burst stimulation (10–30 A, 100 Hz, 20 pulses) to a nearby site of a recorded PHN neuron induced large inward currents and increased the rate of spontaneous inward currents. Even when the PHN was separated from the brainstem slice, the burst stimulation induced the inward currents in PHN neurons in the isolated PHN. The inward currents decreased to about the half by 50 M APV and the residual currents were mostly abolished by a blocker of Ca2+-permeiable AMPA receptor, Naspm (100 M). These results suggest that the inward currents were induced by activation of the local excitatory network in the PHN and Ca2+permeiable AMPA receptor contribute to activation of the network. doi:10.1016/j.neures.2009.09.887
P2-g21 Spatial distribution of simple-spike response of Purkinje cells in the cerebellar nodulus and uvula during vertical head rotation Kenichi Ozawa 1,2 , Toshihiro Kitama 1 , Yu Sato 3 1 Center for Life Science Research, University of Yamanashi, Yamanashi, Japan; 2 Department of Occupational Therapy, Health Science University, Yamanashi, Japan; 3 Department of Physiology, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan