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Common prefrontal activity during inhibition of hand and foot responses
Abstracts P1-g11 Origin of C-terminals in the rat hypoglossal nucleus Yoshinori Haiduka 1 , Toshiyasu Matsui 2 , George Matsumura 1 , Yasushi Kobayashi 2 1
Department of Anatomy, Kyorin University Sch. of Med., Japan; Department of Anatomy and Neurobiology, National Defense Med. Coll., Japan 2
C-terminals are large cholinergic terminals that lie closely apposed to the somata and proximal dendrites of motoneurons innervating the skeletal muscles. We determined the origin of C-terminals in the hypoglossal nucleus (nXII) by tract tracing techniques combined with immunohistochemistry for vesicular acetylcholine transporter (VAChT), a specific marker for cholinergic neurons. We first determined cholinergic neurons projecting to nXII by injecting Fluorogold in the nXII and plotting neurons that showed both the retrograde labeling and the VAChT immunoreactivity. Double-labeled neurons were observed in the pedunculopontine and laterodorsal tegmental nuclei, intermediate reticular formation in the medulla, and layers VI–VII in the spinal cord. We next injected BDA in each of those areas and searched for large terminals on hypoglossal motoneurons that showed both the anterograde labeling and the VAChT immunoreactivity. We have so far confirmed that cholinergic neurons in the intermediate reticular formation gave rise to C-terminals in nXII. doi:10.1016/j.neures.2009.09.465
P1-g12 Common prefrontal activity during inhibition of hand and foot responses Hayato Tabu 1 , Tatsuya Mima 2 , Toshihiko Asou 2 , Hidenao 2 1 Fukuyama , Ryousuke Takahashi 1
Dept Neurol, Kyoto Univ, Kyoto, Japan;
2
HBRC, Kyoto Univ, Kyoto, Japan
Abrupt inhibition of initiated movement which may reflect the prefrontal function is an important piece of human motor control. Typical experimental paradigm to quantify response inhibition is the Stop signal task. Previous fMRI studies using manual Stop signal task showed activated areas in ventrolateral prefrontal cortex (VLPFC) and pre-supplementary motor area (pre-SMA), which might be slightly different for the ocular Stop signal task. To examine whether the prefrontal activations associated with response inhibition of different body parts are common or different, we conducted an fMRI study during the Stop signal task by hand and foot within 13 subjects. Event-related analysis of fMRI data was performed using SPM5, which showed that the bilateral VLPFC and pre-SMA are commonly activated in successful response inhibition both for hand and foot. This indicates the common neural network for inhibition of initiated responses regardless of hand and foot. doi:10.1016/j.neures.2009.09.466
P1-g13 Involvement of human motor cortex in the recognition of hand-written or block letters — A TMS study Masahiro Nakatsuka, Tatsuya Mima, Hidenao Fukuyama Human Brain Research Center, Kyoto Univ, Kyoto, Japan Objective: To investigate the functional involvement of the primary motor cortex (M1) in recognizing letters using motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS). Methods: 11 right-handed healthy volunteers with written informed consents were involved. 30 letters were prepared as the stimuli; 10 small letters of alphabets, 10 Japanese hiragana letters, and 10 kanji letters of daily use in Japan. During the session, subjects look at the the monitor, where the letter stimuli appear in a random order. MEPS were recorded from right first digital interosseus (FDI) muscle,TMSs were given at the timings of 100, 200, 300, 400 or 500 ms following each stimulus onset. Results: For handwritten letters, the mean MEP was significantly inhibited at 300 and 400 ms in comparison to block letters. This result suggests that the hand area of human M1 might be involved in the neural network associated with letter recognition and that the brain representation of hand-written and block letters may be different. doi:10.1016/j.neures.2009.09.467
P1-g14 Altered the timing of intension to move by repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex (M1) Yoshino Ueki, Tatsuya Mima, Hidenao Fukuyama Kyoto University, Japan Previous EEG and fMRI studies indicate that activity in contralateral M1, the supplemental motor area (SMA) and parietal cortex are important in awareness of intention
S105
to move. To clarify the functional relevance of these areas in awareness of intention to move, we used transient suppression of focal neural processing induced by low-frequency rTMS. The experimental paradigm was based on that of Libet. Nine subjects were asked to report the position of the clocks hand at the time they pushed the button (M-judgment) or became aware of their intention to move (W-judgment). 0.9 Hz rTMS was applied over individually-determined left M1, SMA and parietal cortex and measured subsequent task performance before, immediately after and 15 min after rTMS. In W-judgment, rTMS over the left M1 significantly prolonged the W-time immediately after rTMS, while rTMS over the SMA and parietal cortex had no effect. In M-judgment, rTMS had no effect on task performance. The neural processing in contralateral M1 is crucial for awareness of intention to move. doi:10.1016/j.neures.2009.09.468
P1-g15 Functional role of a specialized class of spinal commissural inhibitory neurons during fast escapes in zebrafish Chie Satou 1 , Yukiko Kimura 1 , Tsunehiko Kohashi 2 , Kazuki 3 3 2 Horikawa , Hiroyuki Takeda , Yoichi Oda , Shin-ichi Higashijima 1 1 3
NaOkazaki Inst. for Integrative Biosci., Japan; Tokyo University, Japan
2
Nagoya University, Japan;
In teleost fish, the Mauthner (M)cell, a large reticulo-spinal neuron in the brainstem, triggers escape behavior. Spinal commissural inhibitory interneurons that are electrotonically excited by the M-axon have been identified, but their behavioral roles were unclear. We addressed this issue by using an enhancer-trap line in which the entire population of these neurons (named CoLo: commissural local) was visualized by GFP. In CoLo-ablated larvae, the escape behaviors evoked by sound/vibration stimuli were often impaired with a reduced initial bend of the body, indicating that CoLos play important roles in initiating escapes. We obtained several lines of evidence which strongly suggested that the impaired escapes occurred upon bilateral activation of the M-cells: in normal larvae, CoLo-mediated inhibitory circuits enable animals to perform escapes even in these occasions by silencing the output of the slightly delayed firing of the second M-cell. doi:10.1016/j.neures.2009.09.469
P1-g16 Connections of GABAergic interneurons to corticospinal neurons in the rat motosensory cortex Yasuyo Tanaka 1 , Yasuhiro Tanaka 1 , Takahiro Furuta 1 , Yuchio Yanagawa 2 , Takeshi Kaneko 1,3 1
Department Morphol Brain Sci., Kyoto University, Kyoto, Japan; Department Genetic and Behavioral Neurosci, Gunma University, Maebashi, Japan; 3 CREST, JST, Kawaguchi, Japan 2
In the local circuit of the cerebral cortex, GABAergic inhibitory interneurons work in collaboration with excitatory neurons. In layer V of the motosensory areas, parvalbumin-positive (PV+) interneurons and somatostatin-positive (SOM+) ones constitute about 80% of interneurons. Although these two subtypes were differentiated morphologically, outputs of these subtypes to specific subgroups of cortical neurons have not been studied. Here we combined intracellular single cell staining of interneurons in vitro with the retrograde Golgi-like labeling of corticospinal neurons. We counted close appositions of axonal boutons stained intracellularly and dendrites and cell bodies of corticospinal neurons. The axo-somatic contacts to the corticospinal neurons were seen about 3-fold more frequently with PV+ interneurons than with SOM+ ones. doi:10.1016/j.neures.2009.09.470
P1-g17 The innervation patterns of single subthalamic neurons in rat Yoshinori Koshimizu, Fumino Fujiyama, Kouichi Nakamura, Takahiro Furuta, Takeshi Kaneko Department Morph. Brain, University of Kyoto, Kyoto, Japan The subthalamic nucleus (STh) of the basal ganglia plays a key role in motor control. It is well known that involuntary movement is induced by STh lesions. However, it is still unclear how single STh neurons contribute to motor function, because the understanding of innervation of individual neurons is insufficient. To reveal the detail projection, the single STh neurons in rat were labeled by recombinant Sindbis virus which is designed to express membrane-targeted green fluorescent protein. The axonal arborizations of the single STh neurons were found in the neostriatum, external and internal segment of the globus pallidus (GPe), and substantia nigra pars reticulata. Furthermore, the GPe was divided into CB-rich and -poor regions
Department of Anatomy, Kyorin University Sch. of Med., Japan; Department of Anatomy and Neurobiology, National Defense Med. Coll., Japan 2
C-terminals are large cholinergic terminals that lie closely apposed to the somata and proximal dendrites of motoneurons innervating the skeletal muscles. We determined the origin of C-terminals in the hypoglossal nucleus (nXII) by tract tracing techniques combined with immunohistochemistry for vesicular acetylcholine transporter (VAChT), a specific marker for cholinergic neurons. We first determined cholinergic neurons projecting to nXII by injecting Fluorogold in the nXII and plotting neurons that showed both the retrograde labeling and the VAChT immunoreactivity. Double-labeled neurons were observed in the pedunculopontine and laterodorsal tegmental nuclei, intermediate reticular formation in the medulla, and layers VI–VII in the spinal cord. We next injected BDA in each of those areas and searched for large terminals on hypoglossal motoneurons that showed both the anterograde labeling and the VAChT immunoreactivity. We have so far confirmed that cholinergic neurons in the intermediate reticular formation gave rise to C-terminals in nXII. doi:10.1016/j.neures.2009.09.465
P1-g12 Common prefrontal activity during inhibition of hand and foot responses Hayato Tabu 1 , Tatsuya Mima 2 , Toshihiko Asou 2 , Hidenao 2 1 Fukuyama , Ryousuke Takahashi 1
Dept Neurol, Kyoto Univ, Kyoto, Japan;
2
HBRC, Kyoto Univ, Kyoto, Japan
Abrupt inhibition of initiated movement which may reflect the prefrontal function is an important piece of human motor control. Typical experimental paradigm to quantify response inhibition is the Stop signal task. Previous fMRI studies using manual Stop signal task showed activated areas in ventrolateral prefrontal cortex (VLPFC) and pre-supplementary motor area (pre-SMA), which might be slightly different for the ocular Stop signal task. To examine whether the prefrontal activations associated with response inhibition of different body parts are common or different, we conducted an fMRI study during the Stop signal task by hand and foot within 13 subjects. Event-related analysis of fMRI data was performed using SPM5, which showed that the bilateral VLPFC and pre-SMA are commonly activated in successful response inhibition both for hand and foot. This indicates the common neural network for inhibition of initiated responses regardless of hand and foot. doi:10.1016/j.neures.2009.09.466
P1-g13 Involvement of human motor cortex in the recognition of hand-written or block letters — A TMS study Masahiro Nakatsuka, Tatsuya Mima, Hidenao Fukuyama Human Brain Research Center, Kyoto Univ, Kyoto, Japan Objective: To investigate the functional involvement of the primary motor cortex (M1) in recognizing letters using motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS). Methods: 11 right-handed healthy volunteers with written informed consents were involved. 30 letters were prepared as the stimuli; 10 small letters of alphabets, 10 Japanese hiragana letters, and 10 kanji letters of daily use in Japan. During the session, subjects look at the the monitor, where the letter stimuli appear in a random order. MEPS were recorded from right first digital interosseus (FDI) muscle,TMSs were given at the timings of 100, 200, 300, 400 or 500 ms following each stimulus onset. Results: For handwritten letters, the mean MEP was significantly inhibited at 300 and 400 ms in comparison to block letters. This result suggests that the hand area of human M1 might be involved in the neural network associated with letter recognition and that the brain representation of hand-written and block letters may be different. doi:10.1016/j.neures.2009.09.467
P1-g14 Altered the timing of intension to move by repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex (M1) Yoshino Ueki, Tatsuya Mima, Hidenao Fukuyama Kyoto University, Japan Previous EEG and fMRI studies indicate that activity in contralateral M1, the supplemental motor area (SMA) and parietal cortex are important in awareness of intention
S105
to move. To clarify the functional relevance of these areas in awareness of intention to move, we used transient suppression of focal neural processing induced by low-frequency rTMS. The experimental paradigm was based on that of Libet. Nine subjects were asked to report the position of the clocks hand at the time they pushed the button (M-judgment) or became aware of their intention to move (W-judgment). 0.9 Hz rTMS was applied over individually-determined left M1, SMA and parietal cortex and measured subsequent task performance before, immediately after and 15 min after rTMS. In W-judgment, rTMS over the left M1 significantly prolonged the W-time immediately after rTMS, while rTMS over the SMA and parietal cortex had no effect. In M-judgment, rTMS had no effect on task performance. The neural processing in contralateral M1 is crucial for awareness of intention to move. doi:10.1016/j.neures.2009.09.468
P1-g15 Functional role of a specialized class of spinal commissural inhibitory neurons during fast escapes in zebrafish Chie Satou 1 , Yukiko Kimura 1 , Tsunehiko Kohashi 2 , Kazuki 3 3 2 Horikawa , Hiroyuki Takeda , Yoichi Oda , Shin-ichi Higashijima 1 1 3
NaOkazaki Inst. for Integrative Biosci., Japan; Tokyo University, Japan
2
Nagoya University, Japan;
In teleost fish, the Mauthner (M)cell, a large reticulo-spinal neuron in the brainstem, triggers escape behavior. Spinal commissural inhibitory interneurons that are electrotonically excited by the M-axon have been identified, but their behavioral roles were unclear. We addressed this issue by using an enhancer-trap line in which the entire population of these neurons (named CoLo: commissural local) was visualized by GFP. In CoLo-ablated larvae, the escape behaviors evoked by sound/vibration stimuli were often impaired with a reduced initial bend of the body, indicating that CoLos play important roles in initiating escapes. We obtained several lines of evidence which strongly suggested that the impaired escapes occurred upon bilateral activation of the M-cells: in normal larvae, CoLo-mediated inhibitory circuits enable animals to perform escapes even in these occasions by silencing the output of the slightly delayed firing of the second M-cell. doi:10.1016/j.neures.2009.09.469
P1-g16 Connections of GABAergic interneurons to corticospinal neurons in the rat motosensory cortex Yasuyo Tanaka 1 , Yasuhiro Tanaka 1 , Takahiro Furuta 1 , Yuchio Yanagawa 2 , Takeshi Kaneko 1,3 1
Department Morphol Brain Sci., Kyoto University, Kyoto, Japan; Department Genetic and Behavioral Neurosci, Gunma University, Maebashi, Japan; 3 CREST, JST, Kawaguchi, Japan 2
In the local circuit of the cerebral cortex, GABAergic inhibitory interneurons work in collaboration with excitatory neurons. In layer V of the motosensory areas, parvalbumin-positive (PV+) interneurons and somatostatin-positive (SOM+) ones constitute about 80% of interneurons. Although these two subtypes were differentiated morphologically, outputs of these subtypes to specific subgroups of cortical neurons have not been studied. Here we combined intracellular single cell staining of interneurons in vitro with the retrograde Golgi-like labeling of corticospinal neurons. We counted close appositions of axonal boutons stained intracellularly and dendrites and cell bodies of corticospinal neurons. The axo-somatic contacts to the corticospinal neurons were seen about 3-fold more frequently with PV+ interneurons than with SOM+ ones. doi:10.1016/j.neures.2009.09.470
P1-g17 The innervation patterns of single subthalamic neurons in rat Yoshinori Koshimizu, Fumino Fujiyama, Kouichi Nakamura, Takahiro Furuta, Takeshi Kaneko Department Morph. Brain, University of Kyoto, Kyoto, Japan The subthalamic nucleus (STh) of the basal ganglia plays a key role in motor control. It is well known that involuntary movement is induced by STh lesions. However, it is still unclear how single STh neurons contribute to motor function, because the understanding of innervation of individual neurons is insufficient. To reveal the detail projection, the single STh neurons in rat were labeled by recombinant Sindbis virus which is designed to express membrane-targeted green fluorescent protein. The axonal arborizations of the single STh neurons were found in the neostriatum, external and internal segment of the globus pallidus (GPe), and substantia nigra pars reticulata. Furthermore, the GPe was divided into CB-rich and -poor regions