34 results on '"Tomoko, Yamagata"'
Search Results
2. TRIM26 positively affects hepatitis B virus replication by inhibiting proteasome-dependent degradation of viral core protein
- Author
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Yuki Nakaya, Tsutomu Nishizawa, Hironori Nishitsuji, Hiromi Morita, Tomoko Yamagata, Daichi Onomura, and Kazumoto Murata
- Subjects
Medicine ,Science - Abstract
Abstract Chronic hepatitis B virus (HBV) infection is a major medical concern worldwide. Current treatments for HBV infection effectively inhibit virus replication; however, these treatments cannot cure HBV and novel treatment-strategies should be necessary. In this study, we identified tripartite motif-containing protein 26 (TRIM26) could be a supportive factor for HBV replication. Small interfering RNA-mediated TRIM26 knockdown (KD) modestly attenuated HBV replication in human hepatocytes. Endogenous TRIM26 physically interacted with HBV core protein (HBc), but not polymerase and HBx, through the TRIM26 SPRY domain. Unexpectedly, TRIM26 inhibited HBc ubiquitination even though TRIM26 is an E3 ligase. HBc was degraded by TRIM26 KD in Huh-7 cells, whereas the reduction was restored by a proteasome inhibitor. RING domain-deleted TRIM26 mutant (TRIM26ΔR), a dominant negative form of TRIM26, sequestered TRIM26 from HBc, resulting in promoting HBc degradation. Taking together, this study demonstrated that HBV utilizes TRIM26 to avoid the proteasome-dependent HBc degradation. The interaction between TRIM26 and HBc might be a novel therapeutic target against HBV infection.
- Published
- 2023
- Full Text
- View/download PDF
3. Waking experience modulates sleep need in mice
- Author
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Linus Milinski, Simon P. Fisher, Nanyi Cui, Laura E. McKillop, Cristina Blanco-Duque, Gauri Ang, Tomoko Yamagata, David M. Bannerman, and Vladyslav V. Vyazovskiy
- Subjects
Mice ,EEG ,Sleep homeostasis ,Behaviour ,Wakefulness ,Slow-wave activity ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background Homeostatic regulation of sleep is reflected in the maintenance of a daily balance between sleep and wakefulness. Although numerous internal and external factors can influence sleep, it is unclear whether and to what extent the process that keeps track of time spent awake is determined by the content of the waking experience. We hypothesised that alterations in environmental conditions may elicit different types of wakefulness, which will in turn influence both the capacity to sustain continuous wakefulness as well as the rates of accumulating sleep pressure. To address this, we compared the effects of repetitive behaviours such as voluntary wheel running or performing a simple touchscreen task, with wakefulness dominated by novel object exploration, on sleep timing and EEG slow-wave activity (SWA) during subsequent NREM sleep. Results We find that voluntary wheel running is associated with higher wake EEG theta-frequency activity and results in longer wake episodes, as compared with exploratory behaviour; yet, it does not lead to higher levels of EEG SWA during subsequent NREM sleep in either the frontal or occipital derivation. Furthermore, engagement in a touchscreen task, motivated by food reward, results in lower SWA during subsequent NREM sleep in both derivations, as compared to exploratory wakefulness, even though the total duration of wakefulness is similar. Conclusion Overall, our study suggests that sleep-wake behaviour is highly flexible within an individual and that the homeostatic processes that keep track of time spent awake are sensitive to the nature of the waking experience. We therefore conclude that sleep dynamics are determined, to a large degree, by the interaction between the organism and the environment.
- Published
- 2021
- Full Text
- View/download PDF
4. Deficient synaptic neurotransmission results in a persistent sleep-like cortical activity across vigilance states in mice
- Author
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Mathilde C. C. Guillaumin, Christian D. Harding, Lukas B. Krone, Tomoko Yamagata, Martin C. Kahn, Cristina Blanco-Duque, Gareth T. Banks, Patrick M. Nolan, Stuart N. Peirson, and Vladyslav V. Vyazovskiy
- Abstract
Growing evidence suggests that brain activity during sleep, as well as sleep regulation, are tightly linked with synaptic function and network excitability at the local and global levels. We previously reported that a mutation in synaptobrevin 2 (Vamp2) in restless (rlss) mice results in a marked increase of wakefulness and suppression of sleep, in particular REM sleep (REMS) as well as increased consolidation of sleep and wakefulness. In the current study, using finer-scalein vivoelectrophysiology recordings, we report that spontaneous cortical activity inrlssmice during NREM sleep (NREMS) is characterised by an occurrence of abnormally prolonged periods of complete neuronal silence (OFF-periods), often lasting several seconds, similar to the burst suppression pattern typically seen under deep anaesthesia. Increased incidence of prolonged network OFF-periods was not specific to NREMS, but also present in REMS and wake inrlssmice. Slow-wave activity (SWA) was generally increased inrlssmice, while higher frequencies including theta-frequency activity were decreased, further resulting in diminished differences between vigilance states. The relative increase in SWA after sleep deprivation was attenuated inrlssmice, suggesting either thatrlssmice experience persistently elevated sleep pressure, or, alternatively, that the intrusion of sleep-like patterns of activity into awake state diminishes the accumulation of sleep drive. We propose that deficit in global synaptic neurotransmitter release leads to ‘state inertia’, reflected in an abnormal propensity of brain networks to enter and remain in a persistent ‘default state’ resembling coma or deep anaesthesia.
- Published
- 2023
5. Intracellular chloride regulation mediates local sleep pressure in the cortex
- Author
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Hannah Alfonsa, Richard J. Burman, Paul J. N. Brodersen, Sarah E. Newey, Kashif Mahfooz, Tomoko Yamagata, Marios C. Panayi, David M. Bannerman, Vladyslav V. Vyazovskiy, and Colin J. Akerman
- Subjects
General Neuroscience - Abstract
Extended wakefulness is associated with reduced performance and the build-up of sleep pressure. In the cortex, this manifests as changes in network activity. These changes show local variation depending on the waking experience, and their underlying mechanisms represent targets for overcoming the effects of tiredness. Here, we reveal a central role for intracellular chloride regulation, which sets the strength of postsynaptic inhibition via GABAA receptors in cortical pyramidal neurons. Wakefulness results in depolarizing shifts in the equilibrium potential for GABAA receptors, reflecting local activity-dependent processes during waking and involving changes in chloride cotransporter activity. These changes underlie electrophysiological and behavioral markers of local sleep pressure within the cortex, including the levels of slow-wave activity during non-rapid eye movement sleep and low-frequency oscillatory activity and reduced performance levels in the sleep-deprived awake state. These findings identify chloride regulation as a crucial link between sleep-wake history, cortical activity and behavior.
- Published
- 2022
6. Intracellular chloride regulation mediates local sleep pressure in the cortex
- Author
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Hannah, Alfonsa, Richard J, Burman, Paul J N, Brodersen, Sarah E, Newey, Kashif, Mahfooz, Tomoko, Yamagata, Marios C, Panayi, David M, Bannerman, Vladyslav V, Vyazovskiy, and Colin J, Akerman
- Abstract
Extended wakefulness is associated with reduced performance and the build-up of sleep pressure. In the cortex, this manifests as changes in network activity. These changes show local variation depending on the waking experience, and their underlying mechanisms represent targets for overcoming the effects of tiredness. Here, we reveal a central role for intracellular chloride regulation, which sets the strength of postsynaptic inhibition via GABA
- Published
- 2021
7. Area-specific involvement of frontal areas and the basal ganglia in goal-directed behavior in monkeys
- Author
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Nariko Arimura, Yoshihisa Nakayama, Tomoko Yamagata, and Eiji Hoshi
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Basal ganglia ,Biology ,Goal directed behavior ,Neuroscience - Published
- 2017
8. The hypothalamic link between arousal and sleep homeostasis in mice.
- Author
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Tomoko Yamagata, Kahn, Martin C., Prius-Mengual, José, Meijer, Elise, Šabanović, Merima, Guillaumin, Mathilde C. C., van der Vinne, Vincent, Yi-Ge Huang, McKillop, Laura E., Jagannath, Aarti, Peirson, Stuart N., Mann, Edward O., Foster, Russell G., and Vyazovskiy, Vladyslav V.
- Subjects
- *
PREOPTIC area , *HOMEOSTASIS , *SLEEP , *LABORATORY mice , *INSOMNIACS , *MICE - Abstract
Sleep and wakefulness are not simple, homogenous all-or-none states but represent a spectrum of substates, distinguished by behavior, levels of arousal, and brain activity at the local and global levels. Until now, the role of the hypothalamic circuitry in sleep-wake control was studied primarily with respect to its contribution to rapid state transitions. In contrast, whether the hypothalamus modulates within-state dynamics (state "quality") and the functional significance thereof remains unexplored. Here, we show that photoactivation of inhibitory neurons in the lateral preoptic area (LPO) of the hypothalamus of adult male and female laboratory mice does not merely trigger awakening from sleep, but the resulting awake state is also characterized by an activated electroencephalogram (EEG) pattern, suggesting increased levels of arousal. This was associated with a faster build-up of sleep pressure, as reflected in higher EEG slow-wave activity (SWA) during subsequent sleep. In contrast, photoinhibition of inhibitory LPO neurons did not result in changes in vigilance states but was associated with persistently increased EEG SWA during spontaneous sleep. These findings suggest a role of the LPO in regulating arousal levels, which we propose as a key variable shaping the daily architecture of sleep-wake states. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
9. Visuomotor signals for reaching movements in the rostro-dorsal sector of the monkey thalamic reticular nucleus
- Author
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Léon Tremblay, Yosuke Saga, Ken-ichi Inoue, Eiji Hoshi, Masashi Hashimoto, Masahiko Takada, Tomoko Yamagata, and Yoshihisa Nakayama
- Subjects
Male ,0301 basic medicine ,Dorsum ,Sensory processing ,Movement ,medicine.medical_treatment ,Thalamus ,Inhibitory postsynaptic potential ,Premotor cortex ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Animals ,Neurons ,Thalamic reticular nucleus ,General Neuroscience ,Visually guided ,Motor Cortex ,Haplorhini ,030104 developmental biology ,medicine.anatomical_structure ,nervous system ,Cerebral cortex ,Thalamic Nuclei ,Visual Perception ,Psychology ,Neuroscience ,Psychomotor Performance ,030217 neurology & neurosurgery - Abstract
The thalamic reticular nucleus (TRN) collects inputs from the cerebral cortex and thalamus and, in turn, sends inhibitory outputs to the thalamic relay nuclei. This unique connectivity suggests that the TRN plays a pivotal role in regulating information flow through the thalamus. Here, we analyzed the roles of TRN neurons in visually guided reaching movements. We first used retrograde transneuronal labeling with rabies virus, and showed that the rostro-dorsal sector of the TRN (TRNrd) projected disynaptically to the ventral premotor cortex (PMv). In other experiments, we recorded neurons from the TRNrd or PMv while monkeys performed a visuomotor task. We found that neurons in the TRNrd and PMv showed visual-, set-, and movement-related activity modulation. These results indicate that the TRNrd, as well as the PMv, is involved in the reception of visual signals and in the preparation and execution of reaching movements. The fraction of neurons that were non-selective for the location of visual signals or the direction of reaching movements was greater in the TRNrd than in the PMv. Furthermore, the fraction of neurons whose activity increased from the baseline was greater in the TRNrd than in the PMv. The timing of activity modulation of visual-related and movement-related neurons was comparable in TRNrd and PMv neurons. Overall, our data suggest that TRNrd neurons provide motor thalamic nuclei with inhibitory inputs that are predominantly devoid of spatial selectivity, and that these signals modulate how these nuclei engage in both sensory processing and motor output during visually guided reaching behavior. This article is protected by copyright. All rights reserved.
- Published
- 2016
10. Waking experience modulates sleep need in mice.
- Author
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Milinski, Linus, Fisher, Simon P., Nanyi Cui, McKillop, Laura E., Blanco-Duque, Cristina, Ang, Gauri, Tomoko Yamagata, Bannerman, David M., and Vyazovskiy, Vladyslav V.
- Abstract
Background: Homeostatic regulation of sleep is reflected in the maintenance of a daily balance between sleep and wakefulness. Although numerous internal and external factors can influence sleep, it is unclear whether and to what extent the process that keeps track of time spent awake is determined by the content of the waking experience. We hypothesised that alterations in environmental conditions may elicit different types of wakefulness, which will in turn influence both the capacity to sustain continuous wakefulness as well as the rates of accumulating sleep pressure. To address this, we compared the effects of repetitive behaviours such as voluntary wheel running or performing a simple touchscreen task, with wakefulness dominated by novel object exploration, on sleep timing and EEG slow-wave activity (SWA) during subsequent NREM sleep. Results: We find that voluntary wheel running is associated with higher wake EEG theta-frequency activity and results in longer wake episodes, as compared with exploratory behaviour; yet, it does not lead to higher levels of EEG SWA during subsequent NREM sleep in either the frontal or occipital derivation. Furthermore, engagement in a touchscreen task, motivated by food reward, results in lower SWA during subsequent NREM sleep in both derivations, as compared to exploratory wakefulness, even though the total duration of wakefulness is similar. Conclusion: Overall, our study suggests that sleep-wake behaviour is highly flexible within an individual and that the homeostatic processes that keep track of time spent awake are sensitive to the nature of the waking experience. We therefore conclude that sleep dynamics are determined, to a large degree, by the interaction between the organism and the environment. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
11. Odorant Concentration Differentiator for Intermittent Olfactory Signals
- Author
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Tomoki Kazawa, Terufumi Fujiwara, Keiro Uchino, Ryohei Kanzaki, Shigehiro Namiki, Tomoko Yamagata, Ryota Fukushima, Takeshi Sakurai, and Stephan Shuichi Haupt
- Subjects
Male ,Stimulation ,Sensory system ,Olfaction ,Stimulus (physiology) ,Biology ,Receptors, Odorant ,Olfactory Receptor Neurons ,Animals, Genetically Modified ,Differentiator ,medicine ,Animals ,Olfactory receptor ,Dose-Response Relationship, Drug ,General Neuroscience ,Articles ,Olfactory Pathways ,Bombyx ,Smell ,medicine.anatomical_structure ,Odor ,Odorants ,Female ,Antennal lobe ,Fatty Alcohols ,Neuroscience - Abstract
UTokyo Research掲載「匂いの濃度を効率的に表現する脳の計算メカニズムの発見」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/a-novel-neuronal-mechanism-to-efficiently-code-odorant-concentration/, UTokyo Research "A novel neuronal mechanism to efficiently code odorant concentration" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/a-novel-neuronal-mechanism-to-efficiently-code-odorant-concentration/
- Published
- 2014
12. Rostrocaudal functional gradient among the pre-dorsal premotor cortex, dorsal premotor cortex and primary motor cortex in goal-directed motor behaviour
- Author
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Yoshihisa Nakayama, Eiji Hoshi, and Tomoko Yamagata
- Subjects
0301 basic medicine ,Male ,Computer science ,Posterior parietal cortex ,Motor Activity ,Macaque ,Choice Behavior ,Premotor cortex ,03 medical and health sciences ,0302 clinical medicine ,biology.animal ,medicine ,Animals ,Prefrontal cortex ,Mirror neuron ,Neurons ,biology ,General Neuroscience ,Motor Cortex ,030104 developmental biology ,medicine.anatomical_structure ,Action (philosophy) ,Macaca ,Female ,Primary motor cortex ,Neuroscience ,Goals ,030217 neurology & neurosurgery ,Psychomotor Performance ,Motor cortex - Abstract
The dorsal premotor cortex residing in the dorsolateral aspect of area 6 is a rostrocaudally elongated area that is rostral to the primary motor cortex (M1) and caudal to the prefrontal cortex. This region, which is subdivided into rostral [pre-dorsal premotor cortex (pre-PMd)] and caudal [dorsal premotor cortex proper (PMd)] components, probably plays a central role in planning and executing actions to achieve a behavioural goal. In the present study, we investigated the functional specializations of the pre-PMd, PMd, and M1, because the synthesis of the specific functions performed by each area is considered to be essential. Neurons were recorded while monkeys performed a conditional visuo-goal task designed to include separate processes for determining a behavioural goal (reaching towards a right or left potential target) on the basis of visual object instructions, specifying actions (direction of reaching) to be performed on the basis of the goal, and preparing and executing the action. Neurons in the pre-PMd and PMd retrieved and maintained behavioural goals without encoding the visual features of the visual object instructions, and subsequently specified the actions by multiplexing the goals with the locations of the targets. Furthermore, PMd and M1 neurons played a major role in representing the action during movement preparation and execution, whereas the contribution of the pre-PMd progressively decreased as the time of the actual execution of the movement approached. These findings revealed that the multiple processing stages necessary for the realization of an action to accomplish a goal were implemented in an area-specific manner across a functional gradient from the pre-PMd to M1 that included the PMd as an intermediary.
- Published
- 2015
13. Processing of Visual Signals for Direct Specification of Motor Targets and for Conceptual Representation of Action Targets in the Dorsal and Ventral Premotor Cortex
- Author
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Yoshihisa Nakayama, Eiji Hoshi, Jun Tanji, and Tomoko Yamagata
- Subjects
Male ,Time Factors ,Physiology ,Photic Stimulation ,Movement ,media_common.quotation_subject ,Action Potentials ,Functional Laterality ,Premotor cortex ,Reaction Time ,medicine ,Animals ,Contrast (vision) ,Latency (engineering) ,Sensory cue ,media_common ,Neurons ,Analysis of Variance ,Communication ,business.industry ,General Neuroscience ,Motor Cortex ,Inhibition, Psychological ,Macaca fascicularis ,medicine.anatomical_structure ,Action (philosophy) ,Space Perception ,Laterality ,Female ,Cues ,business ,Psychology ,Neuroscience ,Psychomotor Performance ,Motor cortex - Abstract
Previous reports have indicated that the premotor cortex (PM) uses visual information for either direct guidance of limb movements or indirect specification of action targets at a conceptual level. We explored how visual inputs signaling these two different categories of information are processed by PM neurons. Monkeys performed a delayed reaching task after receiving two different sets of visual instructions, one directly specifying the spatial location of a motor target (a direct spatial-target cue) and the other providing abstract information about the spatial location of a motor target by indicating whether to select the right or left target at a conceptual level (a symbolic action-selection cue). By comparing visual responses of PM neurons to the two sets of visual cues, we found that the conceptual action plan indicated by the symbolic action-selection cue was represented predominantly in dorsal PM (PMd) neurons with a longer latency (150 ms), whereas both PMd and ventral PM (PMv) neurons responded with a shorter latency (90 ms) when the motor target was directly specified with the direct spatial-target cue. We also found that excited, but not inhibited, responses of PM neurons to the direct spatial-target cue were biased toward contralateral preference. In contrast, responses to the symbolic action-selection cue were either excited or inhibited without laterality preference. Taken together, these results suggest that the PM constitutes a pair of distinct circuits for visually guided motor act; one circuit, linked more strongly with PMd, carries information for retrieving action instruction associated with a symbolic cue, and the other circuit, linked with PMd and PMv, carries information for directly specifying a visuospatial position of a reach target.
- Published
- 2009
14. GFP Labeling of Neurosecretory Cells with theGAL4/UASSystem in the Silkmoth Brain Enables Selective Intracellular Staining of Neurons
- Author
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Ryohei Kanzaki, Takeshi Sakurai, Keiro Uchino, Hideki Sezutsu, Tomoko Yamagata, and Toshiki Tamura
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GAL4/UAS system ,Green Fluorescent Proteins ,Biology ,Stain ,Insert (molecular biology) ,Green fluorescent protein ,Animals, Genetically Modified ,Bombyx mori ,Gene expression ,medicine ,Animals ,Prothoracicotropic hormone ,Neurons ,Neuropeptides ,fungi ,Brain ,Biological Transport ,Bombyx ,biology.organism_classification ,Molecular biology ,Cell biology ,medicine.anatomical_structure ,Insect Proteins ,Animal Science and Zoology ,Neuron ,Transcription Factors - Abstract
The microbrain of the silkmoth, Bombyx mori, is a model system for analyzing the neural mechanisms underlying stimulus-driven behavior, and numerous studies using physiological and morphological methods have accumulated. However, one of the limitations of this system is a lack of methodology for labeling specific subsets of neurons. Targeted gene expression with the GAL4/UAS system, which was recently developed, may overcome this disadvantage. To test the GAL4/UAS system in the silkmoth brain, we generated two GAL4 driver lines in which GAL4 expression was under the control of either the bombyxin or prothoracicotropic hormone (PTTH) promoter. Crosses of moths from these lines with a UAS-GFP line showed that green fluorescent protein (GFP) was exclusively expressed in bombyxin or PTTH neurosecretory brain cells. Using these lines, we developed a visually guided method to selectively insert an electrode into and intracellulary stain GFP-expressing cells using fluorescence as a landmark. This work provides a novel method to visualize specific subsets of neurons in the silkmoth brain and to observe detailed structures in a single identified neuron from different individuals.
- Published
- 2008
15. Production of Reactive Oxygen Species and Release of l-Glutamate During Superoxide Anion-Induced Cell Death of Cerebellar Granule Neurons
- Author
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Hiroshi Hatanaka, Yasuyuki Ishikawa, Tomoko Yamagata, Yasushi Enokido, Takumi Satoh, Tadahiro Numakawa, and Yasuhiro Abiru
- Subjects
Anions ,Xanthine Oxidase ,Cerebellum ,Programmed cell death ,Excitotoxicity ,Glutamic Acid ,medicine.disease_cause ,Xanthine ,Biochemistry ,Superoxide dismutase ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,Superoxides ,medicine ,Animals ,Xanthine oxidase ,Cells, Cultured ,Neurons ,chemistry.chemical_classification ,Reactive oxygen species ,Cell Death ,biology ,Superoxide ,Molecular biology ,Rats ,Drug Combinations ,medicine.anatomical_structure ,chemistry ,Catalase ,biology.protein ,Reactive Oxygen Species - Abstract
Enhanced production of superoxide anion (O 2 - ) is considered to play a pivotal role in the pathogenesis of CNS neurons. Here, we report that O 2 - generated by xanthine (XA) + xanthine oxidase (XO) triggered cell death associated with nuclear condensation and DNA fragmentation in cerebellar granule neuron. XA + XO induced significant increases in amounts of intracellular reactive oxygen species (ROS) before initiating loss of cell viability, as determined by measurement of 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate, di(acetoxymethyl ester) (C-DCDHF-DA) for O 2 and other ROS and hydroethidine (HEt) specifically for O 2 by using fluorescence microscopy and flow cytometry. Catalase, but not superoxide dismutase (SOD), significantly protected granule neurons from the XA + XO-induced cell death. Catalase effectively reduced C-DCDHF-DA but not HEt fluorescence, whereas SOD reduced HEt but not C-DCDHF-DA fluorescence, indicating that HEt and C-DCDHF-DA fluorescence correlated with O 2 and hydrogen peroxide, respectively. The NMDA antagonist MK-801 prevented the death. XA + XO induced an increase in L-glutamate release from cerebellar granule neurons. These results indicate that elevation of O 2 induces cell death associated with increasing ROS production in cerebellar granule neurons and that XA + XO enhanced release of L-glutamate.
- Published
- 2002
16. Involvement of the globus pallidus in behavioral goal determination and action specification
- Author
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Yoshihisa Nakayama, Nariko Arimura, Jun Tanji, Eiji Hoshi, and Tomoko Yamagata
- Subjects
Dorsum ,Male ,Frontal cortex ,Time Factors ,Decision Making ,Action Potentials ,Globus Pallidus ,Action selection ,behavioral disciplines and activities ,Premotor cortex ,Basal ganglia ,Neural Pathways ,medicine ,Reaction Time ,Animals ,Neurons ,Analysis of Variance ,General Neuroscience ,Articles ,Magnetic Resonance Imaging ,Frontal Lobe ,Dorsolateral prefrontal cortex ,Macaca fascicularis ,Globus pallidus ,medicine.anatomical_structure ,Action (philosophy) ,nervous system ,Pattern Recognition, Visual ,Female ,Cues ,Psychology ,Neuroscience ,Goals ,psychological phenomena and processes ,Photic Stimulation - Abstract
Multiple loop circuits interconnect the basal ganglia and the frontal cortex, and each part of the cortico-basal ganglia loops plays an essential role in neuronal computational processes underlying motor behavior. To gain deeper insight into specific functions played by each component of the loops, we compared response properties of neurons in the globus pallidus (GP) with those in the dorsal premotor cortex (PMd) and the ventrolateral and dorsolateral prefrontal cortex (vlPFC and dlPFC) while monkeys performed a behavioral task designed to include separate processes for behavioral goal determination and action selection. Initially, visual signals instructed an abstract behavioral goal, and seconds later, a choice cue to select an action was presented. When the instruction cue appeared, GP neurons started to reflect visual features as early as vlPFC neurons. Subsequently, GP neurons began to reflect goals informed by the visual signals no later than neurons in the PMd, vlPFC, and dlPFC, indicating that the GP is involved in the early determination of behavioral goals. In contrast, action specification occurred later in the GP than in the cortical areas, and the GP was not as involved in the process by which a behavioral goal was transformed into an action. Furthermore, the length of time representing behavioral goal and action was shorter in the GP than in the PMd and dlPFC, indicating that the GP may play an important role in detecting individual behavioral events. These observations elucidate the involvement of the GP in goal-directed behavior.
- Published
- 2013
17. [Neural mechanisms underlying the integration of perception and action]
- Author
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Eiji, Hoshi, Yoshihisa, Nakayama, Tomoko, Yamagata, Yosuke, Saga, Masashi, Hashimoto, Nariko, Arimura, and Jun, Tanji
- Subjects
Motor Cortex ,Animals ,Humans ,Prefrontal Cortex ,Perception ,Motor Activity ,Nerve Net ,Frontal Lobe - Abstract
The hallmark of higher-order brain functions is the ability to integrate and associate diverse sets of information in a flexible manner. Thus, fundamental knowledge about the mechanisms underlying of information in the brain can be obtained by examining the neural mechanisms involved in the generation of an appropriate motor command based on perceived sensory signals. In this review article, we have focused on the involvement of the neuronal networks centered at the lateral aspect of the frontal cortex in the process of motor selection and motor planning based on visual signals. We have initially discussed the role of the lateral prefrontal cortex in integrating multiple sets of visual signals to select a reach target and the participation of the premotor cortex in retrieving and integrating diverse sets of motor information, such as where should one reach out or which arm is to be used. Next, based on the results of the studies on ideomotor apraxia, we have hypothesized that there are at least 2 distinct levels of neural representation (virtual level and physical level). We have reviewed the evidence supporting the operation of 2 distinct classes of neuronal activities corresponding to these 2 levels. In conclusion, we propose that the frontal cortex initially processes information across sensory and motor domains at the virtual level to generate information about a forthcoming motor action (virtual action plan) and that this information is subsequently transformed into a motor command, such as muscle activity or movement direction, for an actual body movement at the physical level (physical motor plan). This proposed framework may be useful for explaining the diverse clinical conditions caused by brain lesions as well as for clarifying the neural mechanisms underlying the integration of perception and action.
- Published
- 2011
18. [On somatotopical organization of cortical motor areas]
- Author
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Jun, Tanji, Yoshihisa, Nakayama, Tomoko, Yamagata, and Eiji, Hoshi
- Subjects
Fingers ,Motor Neurons ,Motor Cortex ,Animals ,Humans ,Motor Activity ,Hand ,Muscle, Skeletal - Abstract
Early studies on cortical motor areas have been centered on their somatotopical organization: a reasonable direction of research from the standpoint of skeletomotor control of limb and body movements. On the primary motor cortex, anatomical and physiological studies revealed aspects of somatotopical organization in progressively finer scales. Earlier studies were directed at elucidating the fine-grain modular organization of the primary motor cortex. Later studies, however, emphasized the diversity of output organization in individual part of the cortex, even at a single-cell level. At present, there is no convincing evidence for the existence of microstructures representing any form of unitary function. As for nonprimary motor areas, the existence of somatotopical organization has been inferred based on anatomical studies and on studies utilizing microstimulation. In the supplementary motor area, the body-part representation is broadly organized rostrocaudally in the order of face, forelimb and hindlimb areas, although with an extensive overlap of each area. In contrast, somatotopy is not apparent in the presupplemenetary motor area; effector-independent control of motor behavior seems to be dominant in this area. In the premotor cortex, motor acts involving the hindlimb appears to be much less represented than actions involving hand-arm and face. Overall, in considering the workings of nonprimary areas, aspects of motor behavior involving sensorial guidance, action-selection, or visuomotor association appear to be of primary importance rather than the determination of body parts to be used.
- Published
- 2009
19. Transformation of a virtual action plan into a motor plan in the premotor cortex
- Author
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Yoshihisa Nakayama, Eiji Hoshi, Jun Tanji, and Tomoko Yamagata
- Subjects
Male ,Time Factors ,Action Potentials ,Fixation, Ocular ,Choice Behavior ,Functional Laterality ,Task (project management) ,Premotor cortex ,Conditioning, Psychological ,medicine ,Premovement neuronal activity ,Animals ,Neurons ,Brain Mapping ,General Neuroscience ,Motor Cortex ,Motor control ,Articles ,medicine.anatomical_structure ,Action (philosophy) ,Action plan ,Fixation (visual) ,Macaca ,Female ,Cues ,Psychology ,Neuroscience ,Psychomotor Performance ,Motor cortex - Abstract
Before preparing to initiate a forthcoming motion, we often acquire information about the future action without specifying actual motor parameters. The information for planning an action at this conceptual level can be provided with verbal commands or nonverbal signals even before the associated motor targets are visible. Under these conditions, the information signifying a virtual action plan must be transformed to information that can be used for constructing a motor plan to initiate specific movements. To determine whether the premotor cortex is involved in this process, we examined neuronal activity in the dorsal premotor cortex (PMd) of monkeys performing a behavioral task designed to isolate the behavioral stages of the acquisition of information for a future action and the construction of a motor plan. We trained the animals to receive a symbolic instruction (color and shape of an instruction cue) to determine whether to select the right or left of targets to reach, despite the physical absence of targets. Subsequently, two targets appeared on a screen at different locations. The animals then determined the correct target (left or right) based on the previous instruction and prepared to initiate a reaching movement to an actual target. The experimental design dissociated the selection of the right/left at an abstract level (action plan) from the physical motor plan. Here, we show that activity of individual PMd neurons initially reflects a virtual action plan transcending motor specifics, before these neurons contribute to a transformation process that leads to activity encoding a motor plan.
- Published
- 2008
20. Comparing the involvement of the lateral prefrontal cortex (LPFC) and dorsal premotor cortex (PMd) in representing the virtual action plan and motor plan
- Author
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Yoshihisa Nakayama, Eiji Hoshi, Tomoko Yamagata, and Jun Tanji
- Subjects
Premotor cortex ,Dorsum ,medicine.anatomical_structure ,Working memory ,General Neuroscience ,Action plan ,Motor plan ,medicine ,Posterior parietal cortex ,General Medicine ,Lateral prefrontal cortex ,Psychology ,Neuroscience - Published
- 2011
21. Brain-derived neurotropic factor prevents superoxide anion-induced death of PC12h cells stably expressing TrkB receptor via modulation of reactive oxygen species
- Author
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Atsushi Nakatani, Tomoko Yamagata, Masashi Yamada, Yasuyuki Ishikawa, Takumi Satoh, Hiroshi Hatanaka, and Toshihiko Ikeuchi
- Subjects
Xanthine Oxidase ,Cell Survival ,Tropomyosin receptor kinase B ,Transfection ,PC12 Cells ,Xanthine ,chemistry.chemical_compound ,Neurotrophic factors ,Superoxides ,Animals ,Receptor, trkB ,Nerve Growth Factors ,Xanthine oxidase ,Fluorescent Dyes ,chemistry.chemical_classification ,Brain-derived neurotrophic factor ,Reactive oxygen species ,biology ,Cell Death ,Chemistry ,Superoxide ,General Neuroscience ,Brain-Derived Neurotrophic Factor ,General Medicine ,Recombinant Proteins ,Cell biology ,Rats ,Kinetics ,Nerve growth factor ,Neuroprotective Agents ,nervous system ,Biochemistry ,Microscopy, Fluorescence ,biology.protein ,Reactive Oxygen Species ,Neurotrophin - Abstract
In our previous report (Satoh et al., 1999. Regulation of reactive oxygen species by nerve growth factor but not by Bcl-2 as a novel mechanism of protection of PC12 cells from superoxide anion-induced death. J. Biochem. 125, 952-959), we reported that nerve growth factor (NGF) protected PC12 cells from superoxide anion (O2-)-induced cell death through a novel regulation of reactive oxygen species (ROS) which increased O2- and decreased hydrogen peroxide (H2O2), indicating that decreasing conversion from O2- to H2O2 is a critical process for the protection by NGF. In the present study, we performed a comparative study on protective mechanisms between NGF and brain-derived neurotrophic factor (BDNF) using TrkB-expressing PC12h cells. When compared with NGF, BDNF induced a weaker but significant protective effect on the cells from O2- induced death. BDNF did not seem to change the total amount of ROS in the cells treated with xanthine and xanthine oxidase. On the other hand, BDNF increased O2- and decreased H2O2- levels in the same cells, although not so strongly as NGF. These results suggest that decreasing conversion from O2- to H2O2 is also critical for the protection by BDNF, which is considered to play a central role in survival and differentiation of CNS neurons.
- Published
- 1999
22. Regulation of reactive oxygen species by nerve growth factor but not Bcl-2 as a novel mechanism of protection of PC12 cells from superoxide anion-induced death
- Author
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Yasuo Uchiyama, Hiroshi Hatanaka, Masashi Yamada, Takumi Satoh, Tomoko Yamagata, and Yasuyuki Ishikawa
- Subjects
Oxidative phosphorylation ,medicine.disease_cause ,Biochemistry ,PC12 Cells ,Superoxide dismutase ,chemistry.chemical_compound ,Superoxides ,medicine ,Animals ,Nerve Growth Factors ,Xanthine oxidase ,Molecular Biology ,chemistry.chemical_classification ,Reactive oxygen species ,biology ,Cell Death ,Superoxide ,General Medicine ,Cell biology ,Rats ,Oxidative Stress ,Nerve growth factor ,nervous system ,chemistry ,Proto-Oncogene Proteins c-bcl-2 ,Catalase ,biology.protein ,Reactive Oxygen Species ,Oxidative stress - Abstract
Although neurotrophins protect PC12 cells and neurons from oxidative stress-induced death, the molecular mechanism of this effect is largely unknown. Xanthine (XA)+xanthine oxidase (XO) increased the production of the superoxide anion (O2-) and hydrogen peroxide (H2O2), and the death of PC12 cells. Catalase but not superoxide dismutase (SOD) nor a NO scavenger protected PC12 cells from death, indicating that H2O2 is the main effector responsible for this cell death. Both nerve growth factor (NGF) and Bcl-2 protected PC12 cells from O2--induced toxicity. NGF enhanced the production of O2- and suppressed that of H2O2, suggesting that it inhibits the conversion of O2- to H2O2, while Bcl-2 had no such effect. These results suggested that NGF protected the cells from oxidative stress by altering the composition of the reactive oxygen species (ROS) without affecting their total level.
- Published
- 1999
23. Differential distribution of activities reflecting planning, preparation, and execution of action in six motor areas of the frontal lobe
- Author
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Nariko Arimura, Tomoko Yamagata, Yoshihisa Nakayama, Jun Tanji, and Eiji Hoshi
- Subjects
Motor area ,Frontal lobe ,Action (philosophy) ,General Neuroscience ,General Medicine ,Neuroscience ,Distribution (differential geometry) ,Differential (mathematics) ,Mathematics - Published
- 2011
24. A comparison of neuronal activity of globus pallidus and premotor cortex in retrieving a virtual action plan instructed by a visual object and in developing a physical motor plan
- Author
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Yoshihisa Nakayama, Eiji Hoshi, Nariko Arimura, Tomoko Yamagata, and Jun Tanji
- Subjects
Premotor cortex ,medicine.anatomical_structure ,Globus pallidus ,General Neuroscience ,Action plan ,medicine ,Motor plan ,Premovement neuronal activity ,General Medicine ,Psychology ,Object (computer science) ,Neuroscience - Published
- 2011
25. Involvement of the basal ganglia and the frontal cortex in action planning as mediated by the abstract representation of action
- Author
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Yosuke Saga, Tomoko Yamagata, Nariko Arimura, Jun Tanji, Eiji Hoshi, and Yoshihisa Nakayama
- Subjects
Frontal cortex ,Action (philosophy) ,Action planning ,General Neuroscience ,Basal ganglia ,Representation (systemics) ,General Medicine ,Psychology ,Neuroscience - Published
- 2010
26. Comparison of movement-related neuronal activity recorded from six different areas in the frontal cortex of macaques
- Author
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Nariko Arimura, Yoshihisa Nakayama, Eiji Hoshi, Tomoko Yamagata, and Jun Tanji
- Subjects
Frontal cortex ,Movement (music) ,General Neuroscience ,Premovement neuronal activity ,General Medicine ,Biology ,Neuroscience - Published
- 2010
27. Development and maintenance of neural representation of the motor plan in the dorsal and ventral premotor cortex (PMd and PMv) through distinct paths of information processing
- Author
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Jun Tanji, Eiji Hoshi, Yoshihisa Nakayama, and Tomoko Yamagata
- Subjects
Premotor cortex ,Dorsum ,medicine.anatomical_structure ,Computer science ,General Neuroscience ,Representation (systemics) ,medicine ,Information processing ,Motor plan ,General Medicine ,Neuroscience - Published
- 2010
28. Involvement of lateral prefrontal cortex (LPFC) in a concept-based action planning
- Author
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Eiji Hoshi, Yoshihisa Nakayama, Jun Tanji, and Tomoko Yamagata
- Subjects
Action planning ,Working memory ,General Neuroscience ,Posterior parietal cortex ,General Medicine ,Lateral prefrontal cortex ,Consumer neuroscience ,Psychology ,Neuroscience ,Self-reference effect - Published
- 2009
29. Involvement of subareas within the dorsal premotor area (PMd) in a conceptually demanding visuomotor task
- Author
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Eiji Hoshi, Yoshihisa Nakayama, Nariko Arimura, Jun Tanji, and Tomoko Yamagata
- Subjects
Dorsum ,General Neuroscience ,General Medicine ,Psychology ,Neuroscience ,Task (project management) - Published
- 2009
30. Odorant Concentration Differentiator for Intermittent Olfactory Signals.
- Author
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Terufumi Fujiwara, Tomoki Kazawa, Takeshi Sakurai, Ryota Fukushima, Uchino, Keiro, Tomoko Yamagata, Namiki, Shigehiro, Haupt, Stephan Shuichi, and Ryohei Kanzaki
- Subjects
OLFACTORY receptors ,SPATIOTEMPORAL processes ,SENSORY stimulation ,NEURAL transmission ,PHEROMONES ,SILKWORMS - Abstract
Animals need to discriminate differences in spatiotemporally distributed sensory signals in terms of quality as well as quantity for generating adaptive behavior. Olfactory signals characterized by odor identity and concentration are intermittently distributed in the environment. From these intervals of stimulation, animals process odorant concentration to localize partners or food sources. Although concentration-response characteristics in olfactory neurons have traditionally been investigated using single stimulus pulses, their behavior under intermittent stimulus regimens remains largely elusive. Using the silkmoth (Bombyx morí) pheromone processing system, a simple and behaviorally well-defined model for olfaction, we investigated the neuronal representation of odorant concentration upon intermittent stimulation in the naturally occurring range. To the first stimulus in a series, the responses of antennal lobe (AL) projection neurons (PNs) showed a concentration dependence as previously shown in many olfactory systems. However, PN response amplitudes dynamically changed upon exposure to intermittent stimuli of the same odorant concentration and settled to a constant, largely concentration-independent level. As a result, PN responses emphasized odorant concentration changes rather than encoding absolute concentration in pulse trains of stimuli. Olfactory receptor neurons did not contribute to this response transformation which was due to long-lasting inhibition affecting PNs in the AL. Simulations confirmed that inhibition also provides advantages when stimuli have naturalistic properties. The primary olfactory center thus functions as an odorant concentration differentiator to efficiently detect concentration changes, thereby improving odorant source orientation over a wide concentration range [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
31. 2.P2. Molecular cloning and expression pattern of elav-like genes from silkmoth, Bombyx mori
- Author
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Takeshi Sakurai, Ryohei Kanzaki, T. Tamura, Keiro Uchino, Hideki Sezutsu, and Tomoko Yamagata
- Subjects
Expression pattern ,biology ,Physiology ,Bombyx mori ,Molecular cloning ,biology.organism_classification ,Molecular Biology ,Biochemistry ,Gene ,Cell biology - Published
- 2007
32. 609 Effects of NGF and BDNF on superoxide anion-triggered apoptosis of PC12 cells
- Author
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Tomoko, Yamagata, primary, Takumi, Satoh, additional, Atsushi, Nakatani, additional, Masashi, Yamada, additional, and Hiroshi, Hatanaka, additional
- Published
- 1997
- Full Text
- View/download PDF
33. Involvement of the Globus Pallidus in Behavioral Goal Determination and Action Specification.
- Author
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Nariko Arimura, Yoshihisa Nakayama, Tomoko Yamagata, Jun Tanji, and Eiji Hoshi
- Subjects
GLOBUS pallidus ,ACTION theory (Psychology) ,PREFRONTAL cortex ,NEURAL circuitry ,PREMOTOR cortex ,OBSERVATION (Psychology) - Abstract
Multiple loop circuits interconnect the basal ganglia and the frontal cortex, and each part of the cortico-basal ganglia loops plays an essential role in neuronal computational processes underlying motor behavior. To gain deeper insight into specific functions played by each component of the loops, we compared response properties of neurons in the globus pallidus (GP) with those in the dorsal premotor cortex (PMd) and the ventrolateral and dorsolateral prefrontal cortex (vlPFC and dlPFC) while monkeys performed a behavioral task designed to include separate processes for behavioral goal determination and action selection. Initially, visual signals instructed an abstract behavioral goal, and seconds later, a choice cue to select an action was presented. When the instruction cue appeared,GPneurons started to reflect visual features as early as vlPFC neurons. Subsequently, GP neurons began to reflect goals informed by the visual signals no later than neurons in the PMd, vlPFC, and dlPFC, indicating that the GP is involved in the early determination of behavioral goals. In contrast, action specification occurred later in the GP than in the cortical areas, and the GP was not as involved in the process by which a behavioral goal was transformed into an action. Furthermore, the length of time representing behavioral goal and action was shorter in the GP than in the PMd and dlPFC, indicating that the GP may play an important role in detecting individual behavioral events. These observations elucidate the involvement of the GP in goal-directed behavior. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
34. Processing of Visual Signals for Direct Specification of Motor Targets and for Conceptual Representation of Action Targets in the Dorsal and Ventral Premotor Cortex.
- Author
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Tomoko Yamagata, Yoshihisa Nakayama, Jun Tanji, and Eiji Hoshi
- Abstract
Previous reports have indicated that the premotor cortex (PM) uses visual information for either direct guidance of limb movements or indirect specification of action targets at a conceptual level. We explored how visual inputs signaling these two different categories of information are processed by PM neurons. Monkeys performed a delayed reaching task after receiving two different sets of visual instructions, one directly specifying the spatial location of a motor target (a direct spatial-target cue) and the other providing abstract information about the spatial location of a motor target by indicating whether to select the right or left target at a conceptual level (a symbolic action-selection cue). By comparing visual responses of PM neurons to the two sets of visual cues, we found that the conceptual action plan indicated by the symbolic action-selection cue was represented predominantly in dorsal PM (PMd) neurons with a longer latency (150 ms), whereas both PMd and ventral PM (PMv) neurons responded with a shorter latency (90 ms) when the motor target was directly specified with the direct spatial-target cue. We also found that excited, but not inhibited, responses of PM neurons to the direct spatial-target cue were biased toward contralateral preference. In contrast, responses to the symbolic action-selection cue were either excited or inhibited without laterality preference. Taken together, these results suggest that the PM constitutes a pair of distinct circuits for visually guided motor act; one circuit, linked more strongly with PMd, carries information for retrieving action instruction associated with a symbolic cue, and the other circuit, linked with PMd and PMv, carries information for directly specifying a visuospatial position of a reach target. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
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