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Postural muscle tone synchronizes with automatic nervous activity in very low frequency domain
Abstracts / Neuroscience Research 58S (2007) S1–S244
P3-e27 Postural muscle tone synchronizes with automatic nervous activity in very low frequency domain
S211
Asymmetric adjustments of human target-reaching by P3-e30 target switch
Yifa Jiang 1 , Sachio Nagasaki 2 , Hidenori Kimura 1 1 Biological Control System Laboratory, RIKEN, Nagoya, Japan; 2 Department of Sports Medicine & Sports Science, Gifu University, Gifu, Japan
Satoshi Shibuya 1 , Kazutaka Igarashi 2 , Hideto Sano 2 , Masahito Takahashi 2 , Kazuhiko Satomi 2 , Yukari Ohki 1 1 Dept. Physiol., Kyorin Univ. Sch. Med., Tokyo, Japan; 2 Dept. Orthop. Surg., Kyorin Univ. Sch. Med., Tokyo, Japan
In this present study we measured postural sway, muscle tone and heart rate variability simultaneously to elucidate the relation between spontaneously postural sway, muscle tone and automatic nervous activity in very low frequency (VLF: 0.0033–0.04 Hz) domain of the heart rate variability. Ten healthy young subjects take part in this study. Subjects were asked to stand on a force-plate to keep a static upright stance in 5 min holding a force-transducer consistently by using his/her thumbs and indices. Center-of-pressure (COP), heart-rate-interval and clip forces were recorded and analyzed. The results shown that postural sways are correlated to heart-rate-variability with a correlation coefficient of 0.47 ± 0.12 (p < 0.01), and also coherent with muscle tone significantly in frequency less than 0.03 Hz. The results suggest a common oscillator be situated on the controller center which have an effect on balance-keeping and automatic-nervous-system control simultaneously.
We examined adjustments of ongoing human target-reaching evoked by unexpected switch of targets. Right-handed subjects were required to reach to a lighted center LED (target, 40 cm ahead) by either arms, as rapidly and accurately as possible. The target sometimes switched to either a left or right LED (10 cm from the center) randomly, 25 or 100 ms after the movement initiation. 3D positions of an index finger and EOG were recorded. As reported, subjects could adjust movements at short latencies (>120 ms) after the target switch. But the adjustment was faster and more accurate, when the new target was in the horizontal adduction than abduction direction. In the former, the adjustment was better coordinated with the saccade (onset latency, >120 ms). The tendency was clearer in the dominant arm. The results suggest that normal humans tend to attend around the target asymmetrically, already during reaching. The coordination indicates that the adjustment of the arm movement could use the same drive as the regular saccade.
Research funds: 17560220
P3-e28 Presynaptic AMPA receptors on the corticostriatal terminals enhance the release probability of the synaptic vesicles Tanaka 1 ,
Fujiyama 1 ,
Nomura 2 ,
Takuma Fumino Masaki Toshio Aoyagi 2,3 , Takeshi Kaneko 1,2 1 Department of Morphological Brain Science, Kyoto University, Kyoto, Japan; 2 CREST, JST, Kyoto, Japan; 3 Department of Applied Analysis and Complex Dynamical Systems, Kyoto University, Kyoto, Japan Presynaptic AMPA receptors (preAMPARs) have recently been reported on corticostriatal terminals (CsTs). Constructing a simulation model of a CsT with preAMPAR and a medium-sized spiny neuron (MSN), we tried to reveal the role played by the preAMPARs in the cortico-basal-thalamic loop. High-frequency stimulation of the model CsT enhanced the release probability of synaptic vesicles, and depolarized the membrane potential of the model MSN supralinearly. Injecting a sequence of high- and low-frequency stimulations to the model CsTs, we observed membrane potential fluctuations closely similar to up- and down-state transition in vivo. Research funds: KAKENHI: 16200025, 17022020, 17650100, 16500217, 17022024, 18047014, 18019019, and 18300079
P3-e31 Neural correlates of estimating graspability Satoshi Hirose 1,2 , Nobuhiro Hagura 1,4 , Michikazu Matsumura 1 , Eiichi Naito 2,3 1 Graduate School of Human and Environmental Studies, Kyoto Univ., Kyoto, Japan; 2 ATR Computational Neuroscience Lab., Kyoto, Japan; 3 NICT, Kyoto, Japan; 4 Japan Society for the Promotion of Science, Japan Cognition of one’s own motor capacity in the visual space is essential to select an appropriate motor behavior. In the present study, we utilized functional magnetic resonance imaging to investigate the neuronal correlates of judging one’s own motor capacity. We measured brain activity of 17 right-handed participants while they judged whether visually presented objects are graspable (with their right hand) or not, without making any actual movement. As a control condition, they compared the size of the object with that of their fist. We found that the left dorsal premotor cortex (PMd) was specifically activated under the condition where the participants judged their own graspability, and its activity was correlated with the time required for the judgement. The left PMd is involved in the neuronal computation of one’s own motor capacity, that may be critical for planning an adaptive motor behavior. Research funds: Grant-in-Aid for Scientific Research (C) [KAKENHI 17500209]
P3-e29
P3-e32 GABA-containing ␥-motor neurons
Ryoko Hisamitsu, Hidemasa Furue, Megumu Yoshimura Department of Integrative Physiology, Kyushu University, Fukuoka, Japan
Tetsufumi Ito 1 , Hiroyuki Hioki 2 , Kouichi Nakamura 2,3 , Takeshi Kaneko 2,3 , Yoshiaki Nojyo 1 1 Department of Anatomy, University of Fukui, Fukui, Japan; 2 Department of Morphological Brain Science, Kyoto University, Kyoto, Japan; 3 CREST, Kawaguchi, Japan
Patch-clamp analysis of membrane properties of bursting neurons in the young adult rat ventral horn in vitro
Electrophysiological and morphological properties of ventral horn neurons were investigated using blind patch-clamp recording from spinal cord slices. In lamina IX of the spinal ventral horn, we classified recorded neurons into two types, bursting and silent types (BT and ST), based on their firing properties. BT neurons had rhythmic firing pattern at resting membrane potential. On the other hand, ST neurons did not have any rhythmic firing patterns. Under the voltage-clamp condition, any rhythmic activity of spontaneous EPSCs was not observed in both BT and ST neurons. The results suggest that rhythmic firing in BT neurons is mainly caused by intrinsic membrane properties such as persistent Na+ channel or voltage-dependent Ca2+ channel activities. Such BT neurons may contribute to the central pattern generation in the ventral horn. Research funds: KAKENHI
GABA-containing fibers, identified by antibodies for GABA and GAD67, were found in the ventral roots of C5-T7 spinal segments. They were immunopositive for ChAT, a marker of cholinergic neuron, and were thinner than GABA-negative fibers. GABA-containing fibers were also found in the brachial plexus. Furthermore, GABA-containing terminals made contact with the capsular sleeve of the intrafusal muscle fibers of the upper limb, and were considered as terminals of ␥-motor fibers. After injection of fluorogold (FG), a retrograde tracer, in the forelimb muscles, we processed spinal cord sections for a combined method of immunohistochemistry for FG, and in situ hybridization for GAD67 mRNA, and found that some retrogradely labeled medium-sized neurons in the ventral horn, presumably ␥-motor neurons, express GAD67 mRNA. These observations indicate that some ␥-motor neurons contain GABA. Research funds: KAKENHI 18700339
P3-e27 Postural muscle tone synchronizes with automatic nervous activity in very low frequency domain
S211
Asymmetric adjustments of human target-reaching by P3-e30 target switch
Yifa Jiang 1 , Sachio Nagasaki 2 , Hidenori Kimura 1 1 Biological Control System Laboratory, RIKEN, Nagoya, Japan; 2 Department of Sports Medicine & Sports Science, Gifu University, Gifu, Japan
Satoshi Shibuya 1 , Kazutaka Igarashi 2 , Hideto Sano 2 , Masahito Takahashi 2 , Kazuhiko Satomi 2 , Yukari Ohki 1 1 Dept. Physiol., Kyorin Univ. Sch. Med., Tokyo, Japan; 2 Dept. Orthop. Surg., Kyorin Univ. Sch. Med., Tokyo, Japan
In this present study we measured postural sway, muscle tone and heart rate variability simultaneously to elucidate the relation between spontaneously postural sway, muscle tone and automatic nervous activity in very low frequency (VLF: 0.0033–0.04 Hz) domain of the heart rate variability. Ten healthy young subjects take part in this study. Subjects were asked to stand on a force-plate to keep a static upright stance in 5 min holding a force-transducer consistently by using his/her thumbs and indices. Center-of-pressure (COP), heart-rate-interval and clip forces were recorded and analyzed. The results shown that postural sways are correlated to heart-rate-variability with a correlation coefficient of 0.47 ± 0.12 (p < 0.01), and also coherent with muscle tone significantly in frequency less than 0.03 Hz. The results suggest a common oscillator be situated on the controller center which have an effect on balance-keeping and automatic-nervous-system control simultaneously.
We examined adjustments of ongoing human target-reaching evoked by unexpected switch of targets. Right-handed subjects were required to reach to a lighted center LED (target, 40 cm ahead) by either arms, as rapidly and accurately as possible. The target sometimes switched to either a left or right LED (10 cm from the center) randomly, 25 or 100 ms after the movement initiation. 3D positions of an index finger and EOG were recorded. As reported, subjects could adjust movements at short latencies (>120 ms) after the target switch. But the adjustment was faster and more accurate, when the new target was in the horizontal adduction than abduction direction. In the former, the adjustment was better coordinated with the saccade (onset latency, >120 ms). The tendency was clearer in the dominant arm. The results suggest that normal humans tend to attend around the target asymmetrically, already during reaching. The coordination indicates that the adjustment of the arm movement could use the same drive as the regular saccade.
Research funds: 17560220
P3-e28 Presynaptic AMPA receptors on the corticostriatal terminals enhance the release probability of the synaptic vesicles Tanaka 1 ,
Fujiyama 1 ,
Nomura 2 ,
Takuma Fumino Masaki Toshio Aoyagi 2,3 , Takeshi Kaneko 1,2 1 Department of Morphological Brain Science, Kyoto University, Kyoto, Japan; 2 CREST, JST, Kyoto, Japan; 3 Department of Applied Analysis and Complex Dynamical Systems, Kyoto University, Kyoto, Japan Presynaptic AMPA receptors (preAMPARs) have recently been reported on corticostriatal terminals (CsTs). Constructing a simulation model of a CsT with preAMPAR and a medium-sized spiny neuron (MSN), we tried to reveal the role played by the preAMPARs in the cortico-basal-thalamic loop. High-frequency stimulation of the model CsT enhanced the release probability of synaptic vesicles, and depolarized the membrane potential of the model MSN supralinearly. Injecting a sequence of high- and low-frequency stimulations to the model CsTs, we observed membrane potential fluctuations closely similar to up- and down-state transition in vivo. Research funds: KAKENHI: 16200025, 17022020, 17650100, 16500217, 17022024, 18047014, 18019019, and 18300079
P3-e31 Neural correlates of estimating graspability Satoshi Hirose 1,2 , Nobuhiro Hagura 1,4 , Michikazu Matsumura 1 , Eiichi Naito 2,3 1 Graduate School of Human and Environmental Studies, Kyoto Univ., Kyoto, Japan; 2 ATR Computational Neuroscience Lab., Kyoto, Japan; 3 NICT, Kyoto, Japan; 4 Japan Society for the Promotion of Science, Japan Cognition of one’s own motor capacity in the visual space is essential to select an appropriate motor behavior. In the present study, we utilized functional magnetic resonance imaging to investigate the neuronal correlates of judging one’s own motor capacity. We measured brain activity of 17 right-handed participants while they judged whether visually presented objects are graspable (with their right hand) or not, without making any actual movement. As a control condition, they compared the size of the object with that of their fist. We found that the left dorsal premotor cortex (PMd) was specifically activated under the condition where the participants judged their own graspability, and its activity was correlated with the time required for the judgement. The left PMd is involved in the neuronal computation of one’s own motor capacity, that may be critical for planning an adaptive motor behavior. Research funds: Grant-in-Aid for Scientific Research (C) [KAKENHI 17500209]
P3-e29
P3-e32 GABA-containing ␥-motor neurons
Ryoko Hisamitsu, Hidemasa Furue, Megumu Yoshimura Department of Integrative Physiology, Kyushu University, Fukuoka, Japan
Tetsufumi Ito 1 , Hiroyuki Hioki 2 , Kouichi Nakamura 2,3 , Takeshi Kaneko 2,3 , Yoshiaki Nojyo 1 1 Department of Anatomy, University of Fukui, Fukui, Japan; 2 Department of Morphological Brain Science, Kyoto University, Kyoto, Japan; 3 CREST, Kawaguchi, Japan
Patch-clamp analysis of membrane properties of bursting neurons in the young adult rat ventral horn in vitro
Electrophysiological and morphological properties of ventral horn neurons were investigated using blind patch-clamp recording from spinal cord slices. In lamina IX of the spinal ventral horn, we classified recorded neurons into two types, bursting and silent types (BT and ST), based on their firing properties. BT neurons had rhythmic firing pattern at resting membrane potential. On the other hand, ST neurons did not have any rhythmic firing patterns. Under the voltage-clamp condition, any rhythmic activity of spontaneous EPSCs was not observed in both BT and ST neurons. The results suggest that rhythmic firing in BT neurons is mainly caused by intrinsic membrane properties such as persistent Na+ channel or voltage-dependent Ca2+ channel activities. Such BT neurons may contribute to the central pattern generation in the ventral horn. Research funds: KAKENHI
GABA-containing fibers, identified by antibodies for GABA and GAD67, were found in the ventral roots of C5-T7 spinal segments. They were immunopositive for ChAT, a marker of cholinergic neuron, and were thinner than GABA-negative fibers. GABA-containing fibers were also found in the brachial plexus. Furthermore, GABA-containing terminals made contact with the capsular sleeve of the intrafusal muscle fibers of the upper limb, and were considered as terminals of ␥-motor fibers. After injection of fluorogold (FG), a retrograde tracer, in the forelimb muscles, we processed spinal cord sections for a combined method of immunohistochemistry for FG, and in situ hybridization for GAD67 mRNA, and found that some retrogradely labeled medium-sized neurons in the ventral horn, presumably ␥-motor neurons, express GAD67 mRNA. These observations indicate that some ␥-motor neurons contain GABA. Research funds: KAKENHI 18700339