Suguru Kudoh | Kwansei Gakuin University (original) (raw)

Papers by Suguru Kudoh

2009 International Symposium on Micro-NanoMechatronics and Human Science, 2009

Rat hippocampal neurons were cultured on a dish with 64 micro planer electrodes. We found that th... more Rat hippocampal neurons were cultured on a dish with 64 micro planer electrodes. We found that the silent and reproducible period lasting for 1 sec immediately after the activity evoked in advance. In addition, the repetitive stimuli suppress the spontaneously occurring bursting activity in frequency. These results suggest that distinct internal state of the neuronal circuit was triggered by an electrical stimulation, and these dynamics of network activity may contribute to information processing. In previous study, we developed the neuro-robot system in which the neurons were connected to a robot body and interacted with external world. By utilizing the dynamics of a living neuronal network, it can be designed that, so to speak, the robot, which behaves according to the history of the sensor inputs which the neuronal network has memorized. We are verifying whether the dynamics intrinsic in a neural network can contribute to the action determination of a creature, by moving such a model system.

2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), 2021

In a brain, it is considered that the synchronous activity of neurons expresses a representation ... more In a brain, it is considered that the synchronous activity of neurons expresses a representation of information. Hebb named the synchronous active group of neurons "Cell Assembly". In this study, we hypothesized that a repeatedly expressed pattern is a cell assembly representing a certain kind of information and attempted to extract such "Cell Assembly" by X-means clustering based on spatiotemporal continuity of spontaneous spikes. Moreover, we divided cell assemblies into classes consist of similar types of cell assemblies, using the indiscernibility-based clustering, "rough clustering". As the result, it showed that cell assemblies did not have a large temporal extent, but a spatial extent. Additionally, we analyzed the neuronal network activity as the stochastic process whose state space is the set of cell assembly, finding out that similar patterns appear consecutively. According to these results, information processing in the neuronal network is suggested to be the hierarchical process. Finally, the clustering method was adopted for spontaneous activity and the evoked responses. It is suggested that spontaneous activities and evoked responses are not completely independent, but share resemble activities.

Transactions of the Society of Instrument and Control Engineers, 2006

The Proceedings of Mechanical Engineering Congress, Japan, 2015

Seibutsu Butsuri, 2009

speeds up to SHz all sublects perceived Lolor "hLn LhL rotatien speed was greater than or equal t... more speeds up to SHz all sublects perceived Lolor "hLn LhL rotatien speed was greater than or equal to 3 H7-tth enhanLed effectave connectavity bLL"ecn V4 And V1

Seibutsu Butsuri, 2008

On thL other hand thL CAP peak dmplttude ieduLtions produLed by morphme codeine and LthylmorphmL ... more On thL other hand thL CAP peak dmplttude ieduLtions produLed by morphme codeine and LthylmorphmL dnd also by trdilladel and Ml werL iLldted to theLr chernical strLLLtureg m sLLLh that this Lxtellt en]ianLed with an increase !n the nurllber of

Soft Computing, Nov 1, 2012

The genetical controls are critical for constructing specific circuit in a brain, however, also a... more The genetical controls are critical for constructing specific circuit in a brain, however, also a distant relationship likes a mammal and a bird, the fundamental structure and functions of neurons are preserved. Using Ca2+ imaging of a mixed culture of rat and chick neurons, we elucidated whether the functional connections are formed between neurons from relatively distant species in this study. Periodic and synchronized Ca2+ transients were often observed. Some synchronizations were not strict, suggesting that the bursting activity was loosely transmitted each other. A coculture of rat and chick neuronal cells was possible and some of neurons from distinct species made functional connections, which can be utilized to complementation of damaged neuronal circuit. The mixed circuit of cultured neurons from distinct species is the interesting testing platform for elucidating conditions required for a synaptogenesis and activity of a circuit of neurons from mixed species.

Proceedings of the 8th International Conference on Body Area Networks, 2013

Studies for human-machine interaction such as Brain-Computer Interface (BCI) using EEG has been f... more Studies for human-machine interaction such as Brain-Computer Interface (BCI) using EEG has been focused on. Usability in daily life is critical for BCI. Therefore, a convenient portable telemetry EEG system at low cost is required. We developed "Air Brain system", a portable EEG telemetry system using 3G-network with a smartphone. The feature of the system is recording EEG at low cost, anywhere the system connecting 3G networks. In addition, various sensors on a smartphone are used to sense human behavior during EEG measurement. The system enables us to measure EEG immediately after walking, and we found attenuation of α-wave with eye closing.

Neuroscience Research Supplements, 1993

2008 International Symposium on Micro-NanoMechatronics and Human Science, 2008

ABSTRACT Connections of neurons were once abolished and reorganized complex networks on a culture... more ABSTRACT Connections of neurons were once abolished and reorganized complex networks on a culture dish under rather artificial condition. it observed that a transient characteristic period with high-frequency-burst activity (HFB) of spontaneous action potentials. After the termination of the HFB, we found the spatial distribution of number of spontaneous action potentials was drastically changed to heterogeneous one. We also found history function of this reestablished neuronal network. This reconstructed semi-artificial network performed history dependent response to inputs. That is to say, this historic property was undertaken by a network structure. These results suggest that neuronal network can maintain a kind of "memory".

Proceedings of the 8th International Conference on Body Area Networks, 2013

The re-connection technology for neuronal circuit complements the signal from a brain and transmi... more The re-connection technology for neuronal circuit complements the signal from a brain and transmits it to a peripheral system (body). As a second best plan to reconstruct the neuronal connection, the transplantation of a prosthetic circuit consisting of electrical circuit and / or living neuronal circuit into the patient has been proposed. The semi-artificial living neuronal circuit is useful as a buffer circuit of the brain-device interface. To elucidate characters of the living components of the brain is critical for constructing a functional semi-artificial neuronal circuit. This study confirmed by Ca2+ imaging that functional connections could be formed between neurons derived from different distant species. In addition, the degree and spatiotemporal pattern of the activity in the mixed neuronal circuit was changed by manipulations of the synaptic strength. Especially, neuronal electrical events were strongly activated by the abolishment of inhibitory synaptic inputs. Not only activity pattern but also connectivity between rat and chick neuron was changed by the modification of synaptic efficacy. These results suggested that the mixed circuit of neurons derived from chick and rat is critical model case of an artificial living neuronal circuit.

Electronics and Communications in Japan, 2011

ABSTRACT The fundamental frameworks for possessing qualia are “embodiment” and the network struct... more ABSTRACT The fundamental frameworks for possessing qualia are “embodiment” and the network structures of the relationships between internal modules. We proposed “Anaplastic cognitive agent” (ACA) composed by interactions between submodules with hierarchical history functions and network structures. A dissociated culture system can discriminate several distinct spatiotemporal patterns of action potentials evoked by current inputs, and possesses kinds of history function; history properties of network dynamics, synaptic plasticity, and so on. These features are prerequisite building components of ACA. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(10): 41–56, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10328

Biomedical Vibrational Spectroscopy VI: Advances in Research and Industry, 2014

ABSTRACT The combination of confocal micro-Raman spectroscopy and multivariate analysis is carrie... more ABSTRACT The combination of confocal micro-Raman spectroscopy and multivariate analysis is carried out for analysis of maturation of neurons. This study suggests that Raman data reflects the stages of neural maturation which relates with the expression of new neural function such as spontaneous activity. Neurons obtained from a hippocampus of rat embryos are cultured in a dish with quartz bottom. According to the previous electrophysiological study, matured neural cell network showed regulated pulsation with interval of several seconds without any stimulation. It suggested that alterations in the molecular composition took place in the cell. The Raman measurements are carried out to observe this alteration along with the maturing process of neurons. The spectra of live neural cells measured after 2, 8, 15, 30, 45, 60, 75, 90, 105 and 120 days of culturing are analyzed by principal component analysis (PCA). The result shows several groups suggesting the maturation scheme which is observed by the electrophysiological studies. It demonstrates that the maturation process of neural cells can be monitored by Raman spectroscopy.

Neuroscience Research Supplements, 1994

Neuroscience Research, 1997

S. N. Kudoh’, K. Kiyosue2, M. Kasail, T. Taguchi2 To elucidate the mechanism of synaptic plastici... more S. N. Kudoh’, K. Kiyosue2, M. Kasail, T. Taguchi2 To elucidate the mechanism of synaptic plasticity, synaptic activity of single neuron must be analyzed using multiple methods at the same time. For such analysis, we have developed a dissociated cell culture system, in which we can analyze synaptic events at the level of a single neuron. In this culture, long-lasting enhancement of spontaneous excitatory postsynaptic currents (SEPSCs) was induced by Mg2+-free medium. The enhancement was also induced by transient exposing in conditioned Mg 2f-free medium (CM). This result suggests that a factor(s) which promotes the enhancement is released to the medium during the induction. Boiled CM and a fraction of CM containing molecules smaller than 30 kD had no effect on the amplitude of SEPSCs, suggesting that the factor had rather high molecular mass, not being released small molecules, such as K+ or glutamate. We further revealed that protein kinase C was involved in the mechanism of the enhancement.

Neuroscience Research, 1998

Long-lasting enhancement of spontaneous excitatory postsynaptic currents (SEPSCs) in cultured chi... more Long-lasting enhancement of spontaneous excitatory postsynaptic currents (SEPSCs) in cultured chick cerebral neurons was induced by transient exposure to Mg'-free condition. Brief exposure to a conditioned medium (CM) prepared by Mg'-free treatment of the neurons also induced long-term synaptic enhancement. This suggested that the CM contained a diffusible factor(s) for the potent&ion. which was released during the induction of the potentiation. The factor(s) was revealed to be a protein molecule(s) by heat and trypsin treatment of the CM. The factor(s) induced the potentiation \\ithin 5 min. but it \\as not required for long-lasting maintenance of the increased SEPSCs. Postsynaptic protein synthesis was indispensable to induce the potentiation by the M, CT"-free condition. On the other hand. the potentiation was normally induced by the protein factor(s) even in cyclohesimide. These results suggested that protein synthesis \vas committed to the potentiation at the process bet\%een the activation of NMDA receptors and the secretion ofthe protein factor(s).

IEEJ Transactions on Electrical and Electronic Engineering, 2010

ABSTRACT Neuroscience was initially based on simple computer models, and the resulting assumption... more ABSTRACT Neuroscience was initially based on simple computer models, and the resulting assumption of blocks of information and step-by-step information processing disregards the dynamic features of living neuronal networks. Building semiartificial intelligence in a culture dish using a simple living neuronal network makes comparison with an engineering model easier than when analyzing a complicated brain network. We hypothesize that the status of the neuronal network changes autonomously according to both its own internal state and input from the outer world. Our investigation of such network suggests that an electrical stimulus can make the living neuronal network shift to a particular state, and the response pattern to each input is loosely coupled rather than strictly linked. The critical point we propose regarding brain-like information processing is that the internal state of the autonomous neuronal network is modified by input from the outer world. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

IEEJ Transactions on Electrical and Electronic Engineering, 2011

The complex dynamics of electrical activity in a neuronal network can be effectively analyzed usi... more The complex dynamics of electrical activity in a neuronal network can be effectively analyzed using a small-scale network of cultured living neurons. A multielectrode array culture dish is convenient for this purpose. In this study, we focused on the effects of electrical stimulation on autonomous electrical activity, which included widespread global activity, bursting activity in several parts of the network, and unsynchronized local activity. The electrical stimulation selectively reduced bursting activity in intermediate areas. These results suggest that electrical stimulation not only evoked action potentials but also reduced autonomous activity in a circuit-and frequency-restricted manner. Thus, electrical stimulation changed the internal state of the network.

2009 International Symposium on Micro-NanoMechatronics and Human Science, 2009

Rat hippocampal neurons were cultured on a dish with 64 micro planer electrodes. We found that th... more Rat hippocampal neurons were cultured on a dish with 64 micro planer electrodes. We found that the silent and reproducible period lasting for 1 sec immediately after the activity evoked in advance. In addition, the repetitive stimuli suppress the spontaneously occurring bursting activity in frequency. These results suggest that distinct internal state of the neuronal circuit was triggered by an electrical stimulation, and these dynamics of network activity may contribute to information processing. In previous study, we developed the neuro-robot system in which the neurons were connected to a robot body and interacted with external world. By utilizing the dynamics of a living neuronal network, it can be designed that, so to speak, the robot, which behaves according to the history of the sensor inputs which the neuronal network has memorized. We are verifying whether the dynamics intrinsic in a neural network can contribute to the action determination of a creature, by moving such a model system.

2021 43rd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), 2021

In a brain, it is considered that the synchronous activity of neurons expresses a representation ... more In a brain, it is considered that the synchronous activity of neurons expresses a representation of information. Hebb named the synchronous active group of neurons "Cell Assembly". In this study, we hypothesized that a repeatedly expressed pattern is a cell assembly representing a certain kind of information and attempted to extract such "Cell Assembly" by X-means clustering based on spatiotemporal continuity of spontaneous spikes. Moreover, we divided cell assemblies into classes consist of similar types of cell assemblies, using the indiscernibility-based clustering, "rough clustering". As the result, it showed that cell assemblies did not have a large temporal extent, but a spatial extent. Additionally, we analyzed the neuronal network activity as the stochastic process whose state space is the set of cell assembly, finding out that similar patterns appear consecutively. According to these results, information processing in the neuronal network is suggested to be the hierarchical process. Finally, the clustering method was adopted for spontaneous activity and the evoked responses. It is suggested that spontaneous activities and evoked responses are not completely independent, but share resemble activities.

Transactions of the Society of Instrument and Control Engineers, 2006

The Proceedings of Mechanical Engineering Congress, Japan, 2015

Seibutsu Butsuri, 2009

speeds up to SHz all sublects perceived Lolor "hLn LhL rotatien speed was greater than or equal t... more speeds up to SHz all sublects perceived Lolor "hLn LhL rotatien speed was greater than or equal to 3 H7-tth enhanLed effectave connectavity bLL"ecn V4 And V1

Seibutsu Butsuri, 2008

On thL other hand thL CAP peak dmplttude ieduLtions produLed by morphme codeine and LthylmorphmL ... more On thL other hand thL CAP peak dmplttude ieduLtions produLed by morphme codeine and LthylmorphmL dnd also by trdilladel and Ml werL iLldted to theLr chernical strLLLtureg m sLLLh that this Lxtellt en]ianLed with an increase !n the nurllber of

Soft Computing, Nov 1, 2012

The genetical controls are critical for constructing specific circuit in a brain, however, also a... more The genetical controls are critical for constructing specific circuit in a brain, however, also a distant relationship likes a mammal and a bird, the fundamental structure and functions of neurons are preserved. Using Ca2+ imaging of a mixed culture of rat and chick neurons, we elucidated whether the functional connections are formed between neurons from relatively distant species in this study. Periodic and synchronized Ca2+ transients were often observed. Some synchronizations were not strict, suggesting that the bursting activity was loosely transmitted each other. A coculture of rat and chick neuronal cells was possible and some of neurons from distinct species made functional connections, which can be utilized to complementation of damaged neuronal circuit. The mixed circuit of cultured neurons from distinct species is the interesting testing platform for elucidating conditions required for a synaptogenesis and activity of a circuit of neurons from mixed species.

Proceedings of the 8th International Conference on Body Area Networks, 2013

Studies for human-machine interaction such as Brain-Computer Interface (BCI) using EEG has been f... more Studies for human-machine interaction such as Brain-Computer Interface (BCI) using EEG has been focused on. Usability in daily life is critical for BCI. Therefore, a convenient portable telemetry EEG system at low cost is required. We developed "Air Brain system", a portable EEG telemetry system using 3G-network with a smartphone. The feature of the system is recording EEG at low cost, anywhere the system connecting 3G networks. In addition, various sensors on a smartphone are used to sense human behavior during EEG measurement. The system enables us to measure EEG immediately after walking, and we found attenuation of α-wave with eye closing.

Neuroscience Research Supplements, 1993

2008 International Symposium on Micro-NanoMechatronics and Human Science, 2008

ABSTRACT Connections of neurons were once abolished and reorganized complex networks on a culture... more ABSTRACT Connections of neurons were once abolished and reorganized complex networks on a culture dish under rather artificial condition. it observed that a transient characteristic period with high-frequency-burst activity (HFB) of spontaneous action potentials. After the termination of the HFB, we found the spatial distribution of number of spontaneous action potentials was drastically changed to heterogeneous one. We also found history function of this reestablished neuronal network. This reconstructed semi-artificial network performed history dependent response to inputs. That is to say, this historic property was undertaken by a network structure. These results suggest that neuronal network can maintain a kind of "memory".

Proceedings of the 8th International Conference on Body Area Networks, 2013

The re-connection technology for neuronal circuit complements the signal from a brain and transmi... more The re-connection technology for neuronal circuit complements the signal from a brain and transmits it to a peripheral system (body). As a second best plan to reconstruct the neuronal connection, the transplantation of a prosthetic circuit consisting of electrical circuit and / or living neuronal circuit into the patient has been proposed. The semi-artificial living neuronal circuit is useful as a buffer circuit of the brain-device interface. To elucidate characters of the living components of the brain is critical for constructing a functional semi-artificial neuronal circuit. This study confirmed by Ca2+ imaging that functional connections could be formed between neurons derived from different distant species. In addition, the degree and spatiotemporal pattern of the activity in the mixed neuronal circuit was changed by manipulations of the synaptic strength. Especially, neuronal electrical events were strongly activated by the abolishment of inhibitory synaptic inputs. Not only activity pattern but also connectivity between rat and chick neuron was changed by the modification of synaptic efficacy. These results suggested that the mixed circuit of neurons derived from chick and rat is critical model case of an artificial living neuronal circuit.

Electronics and Communications in Japan, 2011

ABSTRACT The fundamental frameworks for possessing qualia are “embodiment” and the network struct... more ABSTRACT The fundamental frameworks for possessing qualia are “embodiment” and the network structures of the relationships between internal modules. We proposed “Anaplastic cognitive agent” (ACA) composed by interactions between submodules with hierarchical history functions and network structures. A dissociated culture system can discriminate several distinct spatiotemporal patterns of action potentials evoked by current inputs, and possesses kinds of history function; history properties of network dynamics, synaptic plasticity, and so on. These features are prerequisite building components of ACA. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(10): 41–56, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10328

Biomedical Vibrational Spectroscopy VI: Advances in Research and Industry, 2014

ABSTRACT The combination of confocal micro-Raman spectroscopy and multivariate analysis is carrie... more ABSTRACT The combination of confocal micro-Raman spectroscopy and multivariate analysis is carried out for analysis of maturation of neurons. This study suggests that Raman data reflects the stages of neural maturation which relates with the expression of new neural function such as spontaneous activity. Neurons obtained from a hippocampus of rat embryos are cultured in a dish with quartz bottom. According to the previous electrophysiological study, matured neural cell network showed regulated pulsation with interval of several seconds without any stimulation. It suggested that alterations in the molecular composition took place in the cell. The Raman measurements are carried out to observe this alteration along with the maturing process of neurons. The spectra of live neural cells measured after 2, 8, 15, 30, 45, 60, 75, 90, 105 and 120 days of culturing are analyzed by principal component analysis (PCA). The result shows several groups suggesting the maturation scheme which is observed by the electrophysiological studies. It demonstrates that the maturation process of neural cells can be monitored by Raman spectroscopy.

Neuroscience Research Supplements, 1994

Neuroscience Research, 1997

S. N. Kudoh’, K. Kiyosue2, M. Kasail, T. Taguchi2 To elucidate the mechanism of synaptic plastici... more S. N. Kudoh’, K. Kiyosue2, M. Kasail, T. Taguchi2 To elucidate the mechanism of synaptic plasticity, synaptic activity of single neuron must be analyzed using multiple methods at the same time. For such analysis, we have developed a dissociated cell culture system, in which we can analyze synaptic events at the level of a single neuron. In this culture, long-lasting enhancement of spontaneous excitatory postsynaptic currents (SEPSCs) was induced by Mg2+-free medium. The enhancement was also induced by transient exposing in conditioned Mg 2f-free medium (CM). This result suggests that a factor(s) which promotes the enhancement is released to the medium during the induction. Boiled CM and a fraction of CM containing molecules smaller than 30 kD had no effect on the amplitude of SEPSCs, suggesting that the factor had rather high molecular mass, not being released small molecules, such as K+ or glutamate. We further revealed that protein kinase C was involved in the mechanism of the enhancement.

Neuroscience Research, 1998

Long-lasting enhancement of spontaneous excitatory postsynaptic currents (SEPSCs) in cultured chi... more Long-lasting enhancement of spontaneous excitatory postsynaptic currents (SEPSCs) in cultured chick cerebral neurons was induced by transient exposure to Mg'-free condition. Brief exposure to a conditioned medium (CM) prepared by Mg'-free treatment of the neurons also induced long-term synaptic enhancement. This suggested that the CM contained a diffusible factor(s) for the potent&ion. which was released during the induction of the potentiation. The factor(s) was revealed to be a protein molecule(s) by heat and trypsin treatment of the CM. The factor(s) induced the potentiation \\ithin 5 min. but it \\as not required for long-lasting maintenance of the increased SEPSCs. Postsynaptic protein synthesis was indispensable to induce the potentiation by the M, CT"-free condition. On the other hand. the potentiation was normally induced by the protein factor(s) even in cyclohesimide. These results suggested that protein synthesis \vas committed to the potentiation at the process bet\%een the activation of NMDA receptors and the secretion ofthe protein factor(s).

IEEJ Transactions on Electrical and Electronic Engineering, 2010

ABSTRACT Neuroscience was initially based on simple computer models, and the resulting assumption... more ABSTRACT Neuroscience was initially based on simple computer models, and the resulting assumption of blocks of information and step-by-step information processing disregards the dynamic features of living neuronal networks. Building semiartificial intelligence in a culture dish using a simple living neuronal network makes comparison with an engineering model easier than when analyzing a complicated brain network. We hypothesize that the status of the neuronal network changes autonomously according to both its own internal state and input from the outer world. Our investigation of such network suggests that an electrical stimulus can make the living neuronal network shift to a particular state, and the response pattern to each input is loosely coupled rather than strictly linked. The critical point we propose regarding brain-like information processing is that the internal state of the autonomous neuronal network is modified by input from the outer world. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

IEEJ Transactions on Electrical and Electronic Engineering, 2011

The complex dynamics of electrical activity in a neuronal network can be effectively analyzed usi... more The complex dynamics of electrical activity in a neuronal network can be effectively analyzed using a small-scale network of cultured living neurons. A multielectrode array culture dish is convenient for this purpose. In this study, we focused on the effects of electrical stimulation on autonomous electrical activity, which included widespread global activity, bursting activity in several parts of the network, and unsynchronized local activity. The electrical stimulation selectively reduced bursting activity in intermediate areas. These results suggest that electrical stimulation not only evoked action potentials but also reduced autonomous activity in a circuit-and frequency-restricted manner. Thus, electrical stimulation changed the internal state of the network.