高坂 洋史
研究者情報
研究活動情報
論文
- Modular organization of synapses within a neuromere for distinct axial locomotion inDrosophilalarvae
Kazushi Fukumasu; Akinao Nose; Hiroshi Kohsaka
ラスト(シニア)オーサー, bioRxiv, Cold Spring Harbor Laboratory, 出版日 2024年07月02日, Abstract
The ability to generate diverse patterns of behavior is advantageous for animal survival. However, it is still unclear how interneurons in a single nervous system are organized to exhibit distinct motions by coordinating the same set of motor neurons. In this study, we analyze the populational dynamics of synaptic activity when fly larvae exhibit two distinct fictive locomotion, forward and backward waves. Based on neurotransmitter phenotypes, the hemi-neuromere is demarcated into ten domains. Calcium imaging analysis shows that one pair of the domains exhibits a consistent recruitment order in synaptic activity in forward and backward waves, while most other domains show the opposite orders in the distinct fictive locomotion. Connectomics-based mapping indicates that these two domains contain pre- and post-synaptic terminals of interneurons involved in motor control. These results suggest that the identified domains serve as a convergence region of forward and backward crawling programs.
研究論文（学術雑誌）, 英語 - Linking neural circuits to the mechanics of animal behavior in Drosophila larval locomotion
Hiroshi Kohsaka
筆頭著者, Frontiers in Neural Circuits, Frontiers Media SA, 17巻, 掲載ページ 1175899-1175899, 出版日 2023年08月17日, 査読付, 招待, The motions that make up animal behavior arise from the interplay between neural circuits and the mechanical parts of the body. Therefore, in order to comprehend the operational mechanisms governing behavior, it is essential to examine not only the underlying neural network but also the mechanical characteristics of the animal’s body. The locomotor system of fly larvae serves as an ideal model for pursuing this integrative approach. By virtue of diverse investigation methods encompassing connectomics analysis and quantification of locomotion kinematics, research on larval locomotion has shed light on the underlying mechanisms of animal behavior. These studies have elucidated the roles of interneurons in coordinating muscle activities within and between segments, as well as the neural circuits responsible for exploration. This review aims to provide an overview of recent research on the neuromechanics of animal locomotion in fly larvae. We also briefly review interspecific diversity in fly larval locomotion and explore the latest advancements in soft robots inspired by larval locomotion. The integrative analysis of animal behavior using fly larvae could establish a practical framework for scrutinizing the behavior of other animal species.
研究論文（学術雑誌）, 英語 - Synchronous multi-segmental activity between metachronal waves controls locomotion speed in Drosophila larvae
Yingtao Liu; Eri Hasegawa; Akinao Nose; Maarten F Zwart; Hiroshi Kohsaka
ラスト(シニア)オーサー, eLife, eLife Sciences Publications, Ltd, 12巻, 出版日 2023年08月08日, 査読付, The ability to adjust the speed of locomotion is essential for survival. In limbed animals, the frequency of locomotion is modulated primarily by changing the duration of the stance phase. The underlying neural mechanisms of this selective modulation remain an open question. Here, we report a neural circuit controlling a similarly selective adjustment of locomotion frequency in Drosophila larvae. Drosophila larvae crawl using peristaltic waves of muscle contractions. We find that larvae adjust the frequency of locomotion mostly by varying the time between consecutive contraction waves, reminiscent of limbed locomotion. A specific set of muscles, the lateral transverse (LT) muscles, co-contract in all segments during this phase, the duration of which sets the duration of the interwave phase. We identify two types of GABAergic interneurons in the LT neural network, premotor neuron A26f and its presynaptic partner A31c, which exhibit segmentally synchronized activity and control locomotor frequency by setting the amplitude and duration of LT muscle contractions. Altogether, our results reveal an inhibitory central circuit that sets the frequency of locomotion by controlling the duration of the period in between peristaltic waves. Further analysis of the descending inputs onto this circuit will help understand the higher control of this selective modulation.
研究論文（学術雑誌）, 英語 - A vacuum-actuated soft robot inspired by Drosophila larvae to study kinetics of crawling behaviour
Xiyang Sun; Akinao Nose; Hiroshi Kohsaka
ラスト(シニア)オーサー, PLOS ONE, Public Library of Science (PLoS), 18巻, 4号, 掲載ページ e0283316-e0283316, 出版日 2023年04月05日, 査読付, Peristalsis, a motion generated by the propagation of muscular contraction along the body axis, is one of the most common locomotion patterns in limbless animals. While the kinematics of peristalsis has been examined intensively, its kinetics remains unclear, partially due to the lack of suitable physical models to simulate the locomotion patterns and inner drive in soft-bodied animals. Inspired by a soft-bodied animal, Drosophila larvae, we propose a vacuum-actuated soft robot mimicking its crawling behaviour. The soft structure, made of hyperelastic silicone rubber, was designed to imitate the larval segmental hydrostatic structure. Referring to a numerical simulation by the finite element method, the dynamical change in the vacuum pressure in each segment was controlled accordingly, and the soft robots could exhibit peristaltic locomotion. The soft robots successfully reproduced two previous experimental phenomena on fly larvae: 1. Crawling speed in backward crawling is slower than in forward crawling. 2. Elongation of either the segmental contraction duration or intersegmental phase delay makes peristaltic crawling slow. Furthermore, our experimental results provided a novel prediction for the role of the contraction force in controlling the speed of peristaltic locomotion. These observations indicate that soft robots could serve to examine the kinetics of crawling behaviour in soft-bodied animals.
研究論文（学術雑誌）, 英語 - Extraction of bouton-like structures from neuropil calcium imaging data
Kazushi Fukumasu; Akinao Nose; Hiroshi Kohsaka
ラスト(シニア)オーサー, Neural Networks, Elsevier BV, 156巻, 掲載ページ 218-238, 出版日 2022年12月, 査読付
研究論文（学術雑誌） - Electrophysiological validation of monosynaptic connectivity between premotor interneurons and the aCC motoneuron in the Drosophila larval CNS.
Carlo N G Giachello; Iain Hunter; Tom Pettini; Bramwell Coulson; Athene Knufer; Sebastian Cachero; Michael Winding; Aref Arzan Zarin; Hiroshi Kohsaka; Yuen Ngan Fan; Akinao Nose; Matthias Landgraf; Richard A Baines
The Journal of neuroscience : the official journal of the Society for Neuroscience, 出版日 2022年07月20日, 査読付, 国際誌, The Drosophila connectome project aims to map the synaptic connectivity of entire larval and adult fly neural networks, which is essential for understanding nervous system development and function. So far, the project has produced an impressive amount of electron microscopy data that has facilitated reconstructions of specific synapses, including many in the larval locomotor circuit. While this breakthrough represents a technical tour-de-force, the data remain under-utilised, partly due to a lack of functional validation of reconstructions. Attempts to validate connectivity posited by the connectome project, have mostly relied on behavioural assays and/or GRASP or GCaMP imaging. While these techniques are useful, they have limited spatial or temporal resolution. Electrophysiological assays of synaptic connectivity overcome these limitations. Here, we combine patch clamp recordings with optogenetic stimulation in male and female larvae, to test synaptic connectivity proposed by connectome reconstructions. Specifically, we use multiple driver lines to confirm that several connections between premotor interneurons and the anterior corner cell (aCC) motoneuron are, as the connectome project suggests, monosynaptic. In contrast, our results also show that conclusions based on GRASP imaging may provide false positive results regarding connectivity between cells. We also present a novel imaging tool, based on the same technology as our electrophysiology, as a favourable alternative to GRASP. Finally, of eight Gal4 lines tested, five are reliably expressed in the premotors they are targeted to. Thus, our work highlights the need to confirm functional synaptic connectivity, driver line specificity, and use of appropriate genetic tools to support connectome projects.SIGNIFICANCE STATEMENTThe Drosophila connectome project aims to provide a complete description of connectivity between neurons in an organism that presents experimental advantages over other models. It has reconstructed over 80 percent of the fly larva's synaptic connections by manual identification of anatomical landmarks present in serial section transmission electron microscopy (ssTEM) volumes of the larval CNS. We use a highly reliable electrophysiological approach to verify these connections, so provide useful insight into the accuracy of work based on ssTEM. We also present a novel imaging tool for validating excitatory monosynaptic connections between cells, and show that several genetic driver lines designed to target neurons of the larval connectome exhibit non-specific and/or unreliable expression.
研究論文（学術雑誌）, 英語 - A neuromechanical model for Drosophila larval crawling based on physical measurements.
Xiyang Sun; Yingtao Liu; Chang Liu; Koichi Mayumi; Kohzo Ito; Akinao Nose; Hiroshi Kohsaka
ラスト(シニア)オーサー, BMC biology, 20巻, 1号, 掲載ページ 130-130, 出版日 2022年06月15日, 査読付, 国際誌, BACKGROUND: Animal locomotion requires dynamic interactions between neural circuits, the body (typically muscles), and surrounding environments. While the neural circuitry of movement has been intensively studied, how these outputs are integrated with body mechanics (neuromechanics) is less clear, in part due to the lack of understanding of the biomechanical properties of animal bodies. Here, we propose an integrated neuromechanical model of movement based on physical measurements by taking Drosophila larvae as a model of soft-bodied animals. RESULTS: We first characterized the kinematics of forward crawling in Drosophila larvae at a segmental and whole-body level. We then characterized the biomechanical parameters of fly larvae, namely the contraction forces generated by neural activity, and passive elastic and viscosity of the larval body using a stress-relaxation test. We established a mathematical neuromechanical model based on the physical measurements described above, obtaining seven kinematic values characterizing crawling locomotion. By optimizing the parameters in the neural circuit, our neuromechanical model succeeded in quantitatively reproducing the kinematics of larval locomotion that were obtained experimentally. This model could reproduce the observation of optogenetic studies reported previously. The model predicted that peristaltic locomotion could be exhibited in a low-friction condition. Analysis of floating larvae provided results consistent with this prediction. Furthermore, the model predicted a significant contribution of intersegmental connections in the central nervous system, which contrasts with a previous study. This hypothesis allowed us to make a testable prediction for the variability in intersegmental connection in sister species of the genus Drosophila. CONCLUSIONS: We generated a neurochemical model based on physical measurement to provide a new foundation to study locomotion in soft-bodied animals and soft robot engineering.
研究論文（学術雑誌）, 英語 - Regulation of coordinated muscular relaxation in Drosophila larvae by a pattern-regulating intersegmental circuit
Atsuki Hiramoto; Julius Jonaitis; Sawako Niki; Hiroshi Kohsaka; Richard D. Fetter; Albert Cardona; Stefan R. Pulver; Akinao Nose
Nature Communications, Springer Science and Business Media LLC, 12巻, 1号, 掲載ページ 2943-2943, 出版日 2021年12月, 査読付, 国際誌,Abstract Typical patterned movements in animals are achieved through combinations of contraction and delayed relaxation of groups of muscles. However, how intersegmentally coordinated patterns of muscular relaxation are regulated by the neural circuits remains poorly understood. Here, we identify Canon, a class of higher-order premotor interneurons, that regulates muscular relaxation during backward locomotion ofDrosophila larvae. Canon neurons are cholinergic interneurons present in each abdominal neuromere and show wave-like activity during fictive backward locomotion. Optogenetic activation of Canon neurons induces relaxation of body wall muscles, whereas inhibition of these neurons disrupts timely muscle relaxation. Canon neurons provide excitatory outputs to inhibitory premotor interneurons. Canon neurons also connect with each other to form an intersegmental circuit and regulate their own wave-like activities. Thus, our results demonstrate how coordinated muscle relaxation can be realized by an intersegmental circuit that regulates its own patterned activity and sequentially terminates motor activities along the anterior-posterior axis.
研究論文（学術雑誌）, 英語 - Interspecies variation of larval locomotion kinematics in the genus Drosophila and its relation to habitat temperature.
Yuji Matsuo; Akinao Nose; Hiroshi Kohsaka
ラスト(シニア)オーサー, BMC biology, 19巻, 1号, 掲載ページ 176-176, 出版日 2021年09月02日, 査読付, 国際誌, BACKGROUND: Speed and trajectory of locomotion are the characteristic traits of individual species. Locomotion kinematics may have been shaped during evolution towards increased survival in the habitats of each species. Although kinematics of locomotion is thought to be influenced by habitats, the quantitative relation between the kinematics and environmental factors has not been fully revealed. Here, we performed comparative analyses of larval locomotion in 11 Drosophila species. RESULTS: We found that larval locomotion kinematics are divergent among the species. The diversity is not correlated to the body length but is correlated instead to the habitat temperature of the species. Phylogenetic analyses using Bayesian inference suggest that the evolutionary rate of the kinematics is diverse among phylogenetic tree branches. CONCLUSIONS: The results of this study imply that the kinematics of larval locomotion has diverged in the evolutionary history of the genus Drosophila and evolved under the effects of the ambient temperature of habitats.
研究論文（学術雑誌）, 英語 - Optogenetics in Drosophila.
Hiroshi Kohsaka; Akinao Nose
筆頭著者, Advances in experimental medicine and biology, 1293巻, 掲載ページ 309-320, 出版日 2021年, 国際誌, The fruit fly Drosophila melanogaster, an insect 4 mm long, has served as the experimental subject in a wide range of biological research, including neuroscience. In this chapter, we briefly introduce optogenetic applications in Drosophila neuroscience research. First, we describe the development of Drosophila from egg to adult. In fly neuroscience, temperature-controlled perturbation of neural activity, sometimes called "thermogenetics," has been an invaluable tool that predates the advent of optogenetics. After briefly introducing this perturbation technique, we describe the process of generating transgenic flies that express optogenetic probes in a specific group of cells. Transgenic techniques are crucial in the application of optogenetics in Drosophila neuroscience; here we introduce the transposon P-elements, ϕC31 integrase, and CRISPR-Cas9 methods. As for cell-specific gene expression techniques, the binary expression systems utilizing Gal4-UAS, LexA-lexAop, and Q-system are described. We also present a short and basic optogenetic experiment with Drosophila larvae as a practical example. Finally, we review a few recent studies in Drosophila neuroscience that made use of optogenetics. In this overview of fly development, transgenic methods, and applications of optogenetics, we present an introductory background to optogenetics in Drosophila.
研究論文（学術雑誌）, 英語 - Technical Note: Interneurons for Specific Animal Behavior
Kohsaka, Hiroshi; Nose, Akinao
責任著者, CYTOLOGIA, 85巻, 1号, 掲載ページ 1-2, 出版日 2020年03月, 査読付
研究論文（学術雑誌）, 英語 - Regulation of forward and backward locomotion through intersegmental feedback circuits in Drosophila larvae.
Hiroshi Kohsaka; Maarten F Zwart; Akira Fushiki; Richard D Fetter; James W Truman; Albert Cardona; Akinao Nose
責任著者, Nature communications, 10巻, 1号, 掲載ページ 2654-2654, 出版日 2019年06月14日, 査読付, 国際誌, Animal locomotion requires spatiotemporally coordinated contraction of muscles throughout the body. Here, we investigate how contractions of antagonistic groups of muscles are intersegmentally coordinated during bidirectional crawling of Drosophila larvae. We identify two pairs of higher-order premotor excitatory interneurons present in each abdominal neuromere that intersegmentally provide feedback to the adjacent neuromere during motor propagation. The two feedback neuron pairs are differentially active during either forward or backward locomotion but commonly target a group of premotor interneurons that together provide excitatory inputs to transverse muscles and inhibitory inputs to the antagonistic longitudinal muscles. Inhibition of either feedback neuron pair compromises contraction of transverse muscles in a direction-specific manner. Our results suggest that the intersegmental feedback neurons coordinate contraction of synergistic muscles by acting as delay circuits representing the phase lag between segments. The identified circuit architecture also shows how bidirectional motor networks could be economically embedded in the nervous system.
研究論文（学術雑誌）, 英語 - System level analysis of motor-related neural activities in larval Drosophila
Yeongteak Yoon; Jeonghyuk Park; Atsushi Taniguchi; Hiroshi Kohsaka; Ken Nakae; Shigenori Nonaka; Shin Ishii; Akinao Nose
Journal of Neurogenetics, 33巻, 3号, 掲載ページ 179-189, 出版日 2019年06月, 査読付, 国際誌, The way in which the central nervous system (CNS) governs animal movement is complex and difficult to solve solely by the analyses of muscle movement patterns. We tackle this problem by observing the activity of a large population of neurons in the CNS of larval Drosophila. We focused on two major behaviors of the larvae - forward and backward locomotion - and analyzed the neuronal activity related to these behaviors during the fictive locomotion that occurs spontaneously in the isolated CNS. We expressed a genetically-encoded calcium indicator, GCaMP and a nuclear marker in all neurons and then used digitally scanned light-sheet microscopy to record (at a fast frame rate) neural activities in the entire ventral nerve cord (VNC). We developed image processing tools that automatically detected the cell position based on the nuclear staining and allocate the activity signals to each detected cell. We also applied a machine learning-based method that we recently developed to assign motor status in each time frame. Our experimental procedures and computational pipeline enabled systematic identification of neurons that showed characteristic motor activities in larval Drosophila. We found cells whose activity was biased toward forward locomotion and others biased toward backward locomotion. In particular, we identified neurons near the boundary of the subesophageal zone (SEZ) and thoracic neuromeres, which were strongly active during an early phase of backward but not forward fictive locomotion.
研究論文（学術雑誌）, 英語 - Data-driven analysis of motor activity implicates 5-HT2A neurons in backward locomotion of larval Drosophila.
Jeonghyuk Park; Shu Kondo; Hiromu Tanimoto; Hiroshi Kohsaka; Akinao Nose
Scientific reports, 8巻, 1号, 掲載ページ 10307-10307, 出版日 2018年07月09日, 査読付, 国際誌, Rhythmic animal behaviors are regulated in part by neural circuits called the central pattern generators (CPGs). Classifying neural population activities correlated with body movements and identifying the associated component neurons are critical steps in understanding CPGs. Previous methods that classify neural dynamics obtained by dimension reduction algorithms often require manual optimization which could be laborious and preparation-specific. Here, we present a simpler and more flexible method that is based on the pre-trained convolutional neural network model VGG-16 and unsupervised learning, and successfully classifies the fictive motor patterns in Drosophila larvae under various imaging conditions. We also used voxel-wise correlation mapping to identify neurons associated with motor patterns. By applying these methods to neurons targeted by 5-HT2A-GAL4, which we generated by the CRISPR/Cas9-system, we identified two classes of interneurons, termed Seta and Leta, which are specifically active during backward but not forward fictive locomotion. Optogenetic activation of Seta and Leta neurons increased backward locomotion. Conversely, thermogenetic inhibition of 5-HT2A-GAL4 neurons or application of a 5-HT2 antagonist decreased backward locomotion induced by noxious light stimuli. This study establishes an accelerated pipeline for activity profiling and cell identification in larval Drosophila and implicates the serotonergic system in the modulation of backward locomotion.
研究論文（学術雑誌）, 英語 - Divergent Connectivity of Homologous Command-like Neurons Mediates Segment-Specific Touch Responses in Drosophila
Suguru Takagi; Benjamin Thomas Cocanougher; Sawako Niki; Dohjin Miyamoto; Hiroshi Kohsaka; Hokto Kazama; Richard Doty Fetter; James William Truman; Marta Zlatic; Albert Cardona; Akinao Nose
NEURON, CELL PRESS, 96巻, 6号, 掲載ページ 1373-+, 出版日 2017年12月, 査読付, 国際誌, Animals adaptively respond to a tactile stimulus by choosing an ethologically relevant behavior depending on the location of the stimuli. Here, we investigate how somatosensory inputs on different body segments are linked to distinct motor outputs in Drosophila larvae. Larvae escape by backward locomotion when touched on the head, while they crawl forward when touched on the tail. We identify a class of segmentally repeated second-order somatosensory interneurons, that we named Wave, whose activation in anterior and posterior segments elicit backward and forward locomotion, respectively. Anterior and posterior Wave neurons extend their dendrites in opposite directions to receive somatosensory inputs from the head and tail, respectively. Downstream of anterior Wave neurons, we identify premotor circuits including the neuron A03a5, which together with Wave, is necessary for the backward locomotion touch response. Thus, Wave neurons match their receptive field to appropriate motor programs by participating in different circuits in different segments.
研究論文（学術雑誌）, 英語 - Gap Junction-Mediated Signaling from Motor Neurons Regulates Motor Generation in the Central Circuits of Larval Drosophila
Teruyuki Matsunaga; Hiroshi Kohsaka; Akinao Nose
JOURNAL OF NEUROSCIENCE, SOC NEUROSCIENCE, 37巻, 8号, 掲載ページ 2045-2060, 出版日 2017年02月, 査読付, 国際誌, In this study, we used the peristaltic crawling of Drosophila larvae as a model to study how motor patterns are regulated by central circuits. We built an experimental system that allows simultaneous application of optogenetics and calcium imaging to the isolated ventral nerve cord (VNC). We then investigated the effects of manipulating local activity of motor neurons (MNs) on fictive locomotion observed as waves of MN activity propagating along neuromeres. Optical inhibition of MNs with halorhodopsin3 in a middle segment (A4, A5, or A6), but not other segments, dramatically decreased the frequency of the motor waves. Conversely, local activation of MNs with channelrhodopsin2 in a posterior segment (A6 or A7) increased the frequency of the motor waves. Since peripheral nerves mediating sensory feedback were severed in the VNC preparation, these results indicate that MNs send signals to the central circuits to regulate motor pattern generation. Our results also indicate segmental specificity in the roles of MN sin motor control. The effects of the local MN activity manipulation were lost in shaking-B-2 (shakB(2)) or ogre(2), gap-junction mutations in Drosophila, or upon acute application of the gap junction blocker carbenoxolone, implicating electrical synapses in the signaling from MNs. Cell-type-specific RNAi suggested shakB and ogre function in MNs and interneurons, respectively, during the signaling. Our results not only reveal an unexpected role for MNs in motor pattern regulation, but also introduce a powerful experimental system that enables examination of the input-output relationship among the component neurons in this system.
研究論文（学術雑誌）, 英語 - Neural Circuits Underlying Fly Larval Locomotion
Hiroshi Kohsaka; Pierre A. Guertin; Akinao Nose
CURRENT PHARMACEUTICAL DESIGN, BENTHAM SCIENCE PUBL LTD, 23巻, 12号, 掲載ページ 1722-1733, 出版日 2017年, 査読付, 国際誌, Locomotion is a complex motor behavior that may be expressed in different ways using a variety of strategies depending upon species and pathological or environmental conditions. Quadrupedal or bipedal walking, running, swimming, flying and gliding constitute some of the locomotor modes enabling the body, in all cases, to move from one place to another. Despite these apparent differences in modes of locomotion, both vertebrate and invertebrate species share, at least in part, comparable neural control mechanisms for locomotor rhythm and pattern generation and modulation. Significant advances have been made in recent years in studies of the genetic aspects of these control systems. Findings made specifically using Drosophila (fruit fly) models and preparations have contributed to further understanding of the key role of genes in locomotion. This review focuses on some of the main findings made in larval fruit flies while briefly summarizing the basic advantages of using this powerful animal model for studying the neural locomotor system.
研究論文（学術雑誌）, 英語 - Functional dissociation in sweet taste receptor neurons between and within taste organs of Drosophila
Vladimiros Thoma; Stephan Knapek; Shogo Arai; Marion Hartl; Hiroshi Kohsaka; Pudith Sirigrivatanawong; Ayako Abe; Koichi Hashimoto; Hiromu Tanimoto
NATURE COMMUNICATIONS, NATURE PUBLISHING GROUP, 7巻, 掲載ページ 10678-10678, 出版日 2016年02月, 査読付, 国際誌, Finding food sources is essential for survival. Insects detect nutrients with external taste receptor neurons. Drosophila possesses multiple taste organs that are distributed throughout its body. However, the role of different taste organs in feeding remains poorly understood. By blocking subsets of sweet taste receptor neurons, we show that receptor neurons in the legs are required for immediate sugar choice. Furthermore, we identify two anatomically distinct classes of sweet taste receptor neurons in the leg. The axonal projections of one class terminate in the thoracic ganglia, whereas the other projects directly to the brain. These two classes are functionally distinct: the brain-projecting neurons are involved in feeding initiation, whereas the thoracic ganglia-projecting neurons play a role in sugar-dependent suppression of locomotion. Distinct receptor neurons for the same taste quality may coordinate early appetitive responses, taking advantage of the legs as the first appendages to contact food.
研究論文（学術雑誌）, 英語 - A circuit mechanism for the propagation of waves of muscle contraction in Drosophila
Akira Fushiki; Maarten F. Zwart; Hiroshi Kohsaka; Richard D. Fetter; Albert Cardona; Akinao Nose
ELIFE, ELIFE SCIENCES PUBLICATIONS LTD, 5巻, 出版日 2016年02月, 査読付, 国際誌, Animals move by adaptively coordinating the sequential activation of muscles. The circuit mechanisms underlying coordinated locomotion are poorly understood. Here, we report on a novel circuit for the propagation of waves of muscle contraction, using the peristaltic locomotion of Drosophila larvae as a model system. We found an intersegmental chain of synaptically connected neurons, alternating excitatory and inhibitory, necessary for wave propagation and active in phase with the wave. The excitatory neurons (A27h) are premotor and necessary only for forward locomotion, and are modulated by stretch receptors and descending inputs. The inhibitory neurons (GDL) are necessary for both forward and backward locomotion, suggestive of different yet coupled central pattern generators, and its inhibition is necessary for wave propagation. The circuit structure and functional imaging indicated that the commands to contract one segment promote the relaxation of the next segment, revealing a mechanism for wave propagation in peristaltic locomotion.
研究論文（学術雑誌）, 英語 - Functional dissociation in sweet taste receptor neurons between and within taste organs of Drosophila
Vladimiros Thoma; Stephan Knapek; Shogo Arai; Marion Hartl; Hiroshi Kohsaka; Pudith Sirigrivatanawong; Ayako Abe; Koichi Hashimoto; Hiromu Tanimoto
CHEMICAL SENSES, OXFORD UNIV PRESS, 41巻, 9号, 掲載ページ E171-E171, 出版日 2016年11月, 査読付
英語 - Identification of Inhibitory Premotor Interneurons Activated at a Late Phase in a Motor Cycle during Drosophila Larval Locomotion
Yuki Itakura; Hiroshi Kohsaka; Tomoko Ohyama; Marta Zlatic; Stefan R. Pulver; Akinao Nose
PLOS ONE, PUBLIC LIBRARY SCIENCE, 10巻, 9号, 掲載ページ e0136660, 出版日 2015年09月, 査読付, 国際誌, Rhythmic motor patterns underlying many types of locomotion are thought to be produced by central pattern generators (CPGs). Our knowledge of how CPG networks generate motor patterns in complex nervous systems remains incomplete, despite decades of work in a variety of model organisms. Substrate borne locomotion in Drosophila larvae is driven by waves of muscular contraction that propagate through multiple body segments. We use the motor circuitry underlying crawling in larval Drosophila as a model to try to understand how segmentally coordinated rhythmic motor patterns are generated. Whereas muscles, motoneurons and sensory neurons have been well investigated in this system, far less is known about the identities and function of interneurons. Our recent study identified a class of glutamatergic premotor interneurons, PMSIs (period-positive median segmental interneurons), that regulate the speed of locomotion. Here, we report on the identification of a distinct class of glutamatergic premotor interneurons called Glutamatergic Ventro-Lateral Interneurons (GVLIs). We used calcium imaging to search for interneurons that show rhythmic activity and identified GVLIs as interneurons showing wave-like activity during peristalsis. Paired GVLIs were present in each abdominal segment A1-A7 and locally extended an axon towards a dorsal neuropile region, where they formed GRASP-positive putative synaptic contacts with motoneurons. The interneurons expressed vesicular glutamate transporter (vGluT) and thus likely secrete glutamate, a neurotransmitter known to inhibit motoneurons. These anatomical results suggest that GVLIs are premotor interneurons that locally inhibit motoneurons in the same segment. Consistent with this, optogenetic activation of GVLIs with the red-shifted channelrhodopsin, CsChrimson ceased ongoing peristalsis in crawling larvae. Simultaneous calcium imaging of the activity of GVLIs and motoneurons showed that GVLIs' wave-like activity lagged behind that of motoneurons by several segments. Thus, GVLIs are activated when the front of a forward motor wave reaches the second or third anterior segment. We propose that GVLIs are part of the feedback inhibition system that terminates motor activity once the front of the motor wave proceeds to anterior segments.
研究論文（学術雑誌）, 英語 - Optogenetics in Drosophila
Hiroshi Kohsaka; Akinao Nose
Optogenetics: Light-Sensing Proteins and their Applications, Springer Japan, 掲載ページ 199-212, 出版日 2015年01月01日, 査読付, The fruit fly Drosophila melanogaster, an insect 5 mm long, has served as the experimental subject in a wide range of biological research, including neuroscience. In this chapter, we briefly introduce optogenetic applications in Drosophila neuroscience research. First, we describe the development of Drosophila, from egg to adult. In fly neuroscience, temperature-controlled perturbation of neural activity, sometimes called ‘thermogenetics’ has been an invaluable tool that pre-dates the advent of optogenetics. After briefly introducing this perturbation technique, we describe the process of generating transgenic flies that express optogenetic probes in a specific group of cells. Transgenic techniques are crucial in the application of optogenetics in Drosophila neuroscience
here we introduce the transposon P elements and ϕC31 integrase methods. As for cell-specific gene expression techniques, the binary expression systems utilizing Gal4-UAS and LexA-LexAop are described. We also present a short and basic optogenetic experiment with Drosophila larvae as a practical example. Finally, we review a few recent (as of 2014) studies in Drosophila neuroscience that made use of optogenetics. In this overview of fly development, transgenic methods, and applications of optogenetics, we present an introductory background to optogenetics in Drosophila.
論文集(書籍)内論文, 英語 - A Group of Segmental Premotor Interneurons Regulates the Speed of Axial Locomotion in Drosophila Larvae
Hiroshi Kohsaka; Etsuko Takasu; Takako Morimoto; Akinao Nose
CURRENT BIOLOGY, CELL PRESS, 24巻, 22号, 掲載ページ 2632-2642, 出版日 2014年11月, 査読付, 国際誌, Background: Animals control the speed of motion to meet behavioral demands. Yet, the underlying neuronal mechanisms remain poorly understood. Here we show that a class of segmentally arrayed local interneurons (period-positive median segmental interneurons, or PMSIs) regulates the speed of peristaltic locomotion in Drosophila larvae.
Results: PMSIs formed glutamatergic synapses on motor neurons and, when optogenetically activated, inhibited motor activity, indicating that they are inhibitory premotor interneurons. Calcium imaging showed that PMSIs are rhythmically active during peristalsis with a short time delay in relation to motor neurons. Optogenetic silencing of these neurons elongated the duration of motor bursting and greatly reduced the speed of larval locomotion.
Conclusions: Our results suggest that PMSIs control the speed of axial locomotion by limiting, via inhibition, the duration of motor outputs in each segment. Similar mechanisms are found in the regulation of mammalian limb locomotion, suggesting that common strategies may be used to control the speed of animal movements in a diversity of species.
研究論文（学術雑誌）, 英語 - Serotonin and Downstream Leucokinin Neurons Modulate Larval Turning Behavior in Drosophila
Satoko Okusawa; Hiroshi Kohsaka; Akinao Nose
JOURNAL OF NEUROSCIENCE, SOC NEUROSCIENCE, 34巻, 7号, 掲載ページ 2544-2558, 出版日 2014年02月, 査読付, Serotonin (5-HT) is known to modulate motor outputs in a variety of animal behaviors. However, the downstream neural pathways of 5-HT remain poorly understood. We studied the role of 5-HT in directional change, or turning, behavior of fruit fly (Drosophila melanogaster) larvae. We analyzed light-and touch-induced turning and found that turning is a combination of three components: bending, retreating, and rearing. Serotonin transmission suppresses rearing; when we inhibited 5-HT neurons with Shibire or Kir2.1, rearing increased without affecting the occurrence of bending or retreating. Increased rearing in the absence of 5-HT transmission often results in slower or failed turning, indicating that suppression of rearing by 5-HT is critical for successful turning. We identified a class of abdominal neurons called the abdominal LK neurons (ABLKs), which express the 5-HT1B receptor and the neuropeptide leucokinin, as downstream targets of 5-HT that are involved in the control of turning. Increased rearing was observed when neural transmission or leucokinin synthesis was inhibited in these cells. Forced activation of ABLKs also increased rearing, suggesting that an appropriate level of ABLK activity is critical for the control of turning. Calcium imaging revealed that ABLKs show periodic activation with an interval of similar to 15 s. The activity level of ABLKs increased and decreased in response to a 5-HT agonist and antagonist, respectively. Our results suggest that 5-HT modulates larval turning by regulating the activity level of downstream ABLK neurons and secretion of the neuropeptide leucokinin.
研究論文（学術雑誌）, 英語 - Serotonin and Downstream Leucokinin Neurons Modulate Larval Turning Behavior in Drosophila
Satoko Okusawa; Hiroshi Kohsaka; Akinao Nose
JOURNAL OF NEUROSCIENCE, SOC NEUROSCIENCE, 34巻, 7号, 掲載ページ 2544-2558, 出版日 2014年02月, 査読付, 国際誌, Serotonin (5-HT) is known to modulate motor outputs in a variety of animal behaviors. However, the downstream neural pathways of 5-HT remain poorly understood. We studied the role of 5-HT in directional change, or turning, behavior of fruit fly (Drosophila melanogaster) larvae. We analyzed light-and touch-induced turning and found that turning is a combination of three components: bending, retreating, and rearing. Serotonin transmission suppresses rearing; when we inhibited 5-HT neurons with Shibire or Kir2.1, rearing increased without affecting the occurrence of bending or retreating. Increased rearing in the absence of 5-HT transmission often results in slower or failed turning, indicating that suppression of rearing by 5-HT is critical for successful turning. We identified a class of abdominal neurons called the abdominal LK neurons (ABLKs), which express the 5-HT1B receptor and the neuropeptide leucokinin, as downstream targets of 5-HT that are involved in the control of turning. Increased rearing was observed when neural transmission or leucokinin synthesis was inhibited in these cells. Forced activation of ABLKs also increased rearing, suggesting that an appropriate level of ABLK activity is critical for the control of turning. Calcium imaging revealed that ABLKs show periodic activation with an interval of similar to 15 s. The activity level of ABLKs increased and decreased in response to a 5-HT agonist and antagonist, respectively. Our results suggest that 5-HT modulates larval turning by regulating the activity level of downstream ABLK neurons and secretion of the neuropeptide leucokinin.
研究論文（学術雑誌）, 英語 - Optogenetic perturbation of neural activity with laser illumination in semi-intact drosophila larvae in motion.
Teruyuki Matsunaga; Akira Fushiki; Akinao Nose; Hiroshi Kohsaka
Journal of visualized experiments : JoVE, 77号, 掲載ページ e50513, 出版日 2013年07月04日, 査読付, 国際誌, Drosophila larval locomotion is a splendid model system in developmental and physiological neuroscience, by virtue of the genetic accessibility of the underlying neuronal components in the circuits(1-6). Application of optogenetics(7,8) in the larval neural circuit allows us to manipulate neuronal activity in spatially and temporally patterned ways(9-13). Typically, specimens are broadly illuminated with a mercury lamp or LED, so specificity of the target neurons is controlled by binary gene expression systems such as the Gal4-UAS system(14,15). In this work, to improve the spatial resolution to "sub-genetic resolution", we locally illuminated a subset of neurons in the ventral nerve cord using lasers implemented in a conventional confocal microscope. While monitoring the motion of the body wall of the semi-intact larvae, we interactively activated or inhibited neural activity with channelrhodopsin(16,17) or halorhodopsin(18-20), respectively. By spatially and temporally restricted illumination of the neural tissue, we can manipulate the activity of specific neurons in the circuit at a specific phase of behavior. This method is useful for studying the relationship between the activities of a local neural assembly in the ventral nerve cord and the spatiotemporal pattern of motor output.
研究論文（学術雑誌）, 英語 - Role of Sensory Experience in Functional Development of Drosophila Motor Circuits
Akira Fushiki; Hiroshi Kohsaka; Akinao Nose
PLOS ONE, PUBLIC LIBRARY SCIENCE, 8巻, 4号, 掲載ページ e62199, 出版日 2013年04月, 査読付, 国際誌, Neuronal circuits are formed according to a genetically predetermined program and then reconstructed in an experience-dependent manner. While the existence of experience-dependent plasticity has been demonstrated for the visual and other sensory systems, it remains unknown whether this is also the case for motor systems. Here we examined the effects of eliminating sensory inputs on the development of peristaltic movements in Drosophila embryos and larvae. The peristalsis is initially slow and uncoordinated, but gradually develops into a mature pattern during late embryonic stages. We tested whether inhibiting the transmission of specific sensory neurons during this period would have lasting effects on the properties of the sensorimotor circuits. We applied Shibire-mediated inhibition for six hours during embryonic development (15-21 h after egg laying [AEL]) and studied its effects on peristalsis in the mature second-and third-instar larvae. We found that inhibition of chordotonal organs, but not multidendritic neurons, led to a lasting decrease in the speed of larval locomotion. To narrow down the sensitive period, we applied shorter inhibition at various embryonic and larval stages and found that two-hour inhibition during 16-20 h AEL, but not at earlier or later stages, was sufficient to cause the effect. These results suggest that neural activity mediated by specific sensory neurons is involved in the maturation of sensorimotor circuits in Drosophila and that there is a critical period for this plastic change. Consistent with a role of chordotonal neurons in sensory feedback, these neurons were activated during larval peristalsis and acute inhibition of their activity decreased the speed of larval locomotion.
研究論文（学術雑誌）, 英語 - Development of larval motor circuits in Drosophila
Hiroshi Kohsaka; Satoko Okusawa; Yuki Itakura; Akira Fushiki; Akinao Nose
DEVELOPMENT GROWTH & DIFFERENTIATION, WILEY-BLACKWELL, 54巻, 3号, 掲載ページ 408-419, 出版日 2012年04月, 査読付, How are functional neural circuits formed during development? Despite recent advances in our understanding of the development of individual neurons, little is known about how complex circuits are assembled to generate specific behaviors. Here, we describe the ways in which Drosophila motor circuits serve as an excellent model system to tackle this problem. We first summarize what has been learned during the past decades on the connectivity and development of component neurons, in particular motor neurons and sensory feedback neurons. We then review recent progress in our understanding of the development of the circuits as well as studies that apply optogenetics and other innovative techniques to dissect the circuit diagram. New approaches using Drosophila as a model system are now making it possible to search for developmental rules that regulate the construction of neural circuits.
英語 - Development of larval motor circuits in Drosophila
Hiroshi Kohsaka; Satoko Okusawa; Yuki Itakura; Akira Fushiki; Akinao Nose
DEVELOPMENT GROWTH & DIFFERENTIATION, WILEY-BLACKWELL, 54巻, 3号, 掲載ページ 408-419, 出版日 2012年04月, 査読付, 国内誌, How are functional neural circuits formed during development? Despite recent advances in our understanding of the development of individual neurons, little is known about how complex circuits are assembled to generate specific behaviors. Here, we describe the ways in which Drosophila motor circuits serve as an excellent model system to tackle this problem. We first summarize what has been learned during the past decades on the connectivity and development of component neurons, in particular motor neurons and sensory feedback neurons. We then review recent progress in our understanding of the development of the circuits as well as studies that apply optogenetics and other innovative techniques to dissect the circuit diagram. New approaches using Drosophila as a model system are now making it possible to search for developmental rules that regulate the construction of neural circuits.
研究論文（学術雑誌）, 英語 - Optical Dissection of Neural Circuits Responsible for Drosophila Larval Locomotion with Halorhodopsin
Kengo Inada; Hiroshi Kohsaka; Etsuko Takasu; Teruyuki Matsunaga; Akinao Nose
PLOS ONE, PUBLIC LIBRARY SCIENCE, 6巻, 12号, 掲載ページ e29019, 出版日 2011年12月, 査読付, 国際誌, Halorhodopsin (NpHR), a light-driven microbial chloride pump, enables silencing of neuronal function with superb temporal and spatial resolution. Here, we generated a transgenic line of Drosophila that drives expression of NpHR under control of the Gal4/UAS system. Then, we used it to dissect the functional properties of neural circuits that regulate larval peristalsis, a continuous wave of muscular contraction from posterior to anterior segments. We first demonstrate the effectiveness of NpHR by showing that global and continuous NpHR-mediated optical inhibition of motor neurons or sensory feedback neurons induce the same behavioral responses in crawling larvae to those elicited when the function of these neurons are inhibited by Shibire ts, namely complete paralyses or slowed locomotion, respectively. We then applied transient and/or focused light stimuli to inhibit the activity of motor neurons in a more temporally and spatially restricted manner and studied the effects of the optical inhibition on peristalsis. When a brief light stimulus (1-10 sec) was applied to a crawling larva, the wave of muscular contraction stopped transiently but resumed from the halted position when the light was turned off. Similarly, when a focused light stimulus was applied to inhibit motor neurons in one or a few segments which were about to be activated in a dissected larva undergoing fictive locomotion, the propagation of muscular constriction paused during the light stimulus but resumed from the halted position when the inhibition (>5 sec) was removed. These results suggest that (1) Firing of motor neurons at the forefront of the wave is required for the wave to proceed to more anterior segments, and (2) The information about the phase of the wave, namely which segment is active at a given time, can be memorized in the neural circuits for several seconds.
研究論文（学術雑誌）, 英語 - Target recognition at the tips of postsynaptic filopodia: accumulation and function of Capricious
Hiroshi Kohsaka; Akinao Nose
DEVELOPMENT, COMPANY OF BIOLOGISTS LTD, 136巻, 7号, 掲載ページ 1127-1135, 出版日 2009年04月, 査読付, 国際誌, While much evidence suggests that postsynaptic dynamism contributes to the formation of synapses, few studies have addressed its possible role in target selection. Do postsynaptic motile structures seek specific synaptic partner cells, as does the presynaptic growth cone? Here we studied the dynamics of myopodia, postsynaptic filopodia in Drosophila muscles, and the role of Capricious (CAPS) during the process of synaptic matchmaking. CAPS is a target recognition molecule with an extracellular domain containing leucine-rich repeat sequences. It is expressed in specific subsets of embryonic/larval body wall muscles, including muscle 12 (M12). We provide evidence that implicates the tips of myopodia as loci of initial neuromuscular recognition: (1) CAPS, expressed as a GFP-fusion protein in M12, accumulated at the tips of myopodia; and (2) simultaneous live imaging of presynaptic motoneurons and postsynaptic myopodia revealed that initial neuromuscular contacts occur at the tips of myopodia. The live imaging also showed that individual postsynaptic myopodia appear to be able to discriminate partner and non-partner presynaptic cells: whereas many myopodial contacts with the partner motoneurons are stabilized to form synapses, those with non-partner neurons are retracted. In caps mutants, or in double mutants lacking both CAPS and the closely related protein Tartan, we observed fewer contacts between myopodia of M12 and the presynaptic growth cones during the process of initial neuromuscular interaction. The nascent synaptic sites of M12 were also reduced. These results provide evidence for the sensing function of postsynaptic filopodia, and implicate Caps-mediated recognition at the tips of myopodia in synaptic matching.
研究論文（学術雑誌）, 英語 - 3P-233 ぜん動運動を制御する神経回路の形成と可塑性の解析(神経回路・脳の情報処理,第46回日本生物物理学会年会)
Tachi Yukari; Kohsaka Hiroshi; Nose Akinao
生物物理, 一般社団法人 日本生物物理学会, 48巻, 掲載ページ S163, 出版日 2008年
英語 - In vivo induction of postsynaptic molecular assembly by the cell adhesion molecule Fasciclin2
Hiroshi Kohsaka; Etsuko Takasu; Akinao Nose
JOURNAL OF CELL BIOLOGY, ROCKEFELLER UNIV PRESS, 179巻, 6号, 掲載ページ 1289-1300, 出版日 2007年12月, 査読付, 国際誌, Cell adhesion molecules (CAMs) are thought to mediate interactions between innervating axons and their targets. However, such interactions have not been directly observed in vivo. In this paper, we study the function and dynamics of Fasciclin2 (Fas2), a homophilic CAM expressed both pre- and postsynaptically during neuromuscular synapse formation in Drosophila melanogaster. We apply live imaging of functional fluorescent fusion proteins expressed in muscles and find that Fas2 and Discs-Large (Dlg; a scaffolding protein known to bind Fas2) accumulate at the synaptic contact site soon after the arrival of the nerve. Genetic, deletion, and photobleaching analyses suggest that Fas2-mediated trans-synaptic adhesion is important for the postsynaptic accumulation of both Fas2 itself and Dlg. In fas2 mutants, many aspects of synapse formation appear normal; however, we see a reduction in the synaptic accumulation of Scribble (another scaffolding protein) and glutamate receptor subunits GluRIIA and GluRIIB. We propose that Fas2 mediates trans-synaptic adhesion, which contributes to postsynaptic molecular assembly at the onset of synaptogenesis.
研究論文（学術雑誌）, 英語 - S1g1-2 Dynamism and regulation of synaptic assembly at the neuromuscular junction in Drosophila(S1-g1: "Molecular Mechanisms of Axon Targeting and Synaptogensis",Symposia,Abstract,Meeting Program of EABS & BSJ 2006)
Nose Akinao; Kohsaka Hiroshi; Takasu Etsuko
生物物理, 一般社団法人 日本生物物理学会, 46巻, 2号, 掲載ページ S111, 出版日 2006年
英語 - 1M1045 シナプス形成初期における標的認識分子カプリシャスの可視化(15.神経・感覚,一般演題,日本生物物理学会第40回年会)
高坂 洋史; 能瀬 聡直
生物物理, 一般社団法人 日本生物物理学会, 42巻, 2号, 掲載ページ S75, 出版日 2002年
日本語
MISC
- 複数の運動出力パターンを生み出す神経ネットワーク構造
高坂 洋史
ニューサイエンス社, 出版日 2022年02月20日, 月刊細胞, 54巻, 2号, 掲載ページ 47-49, 日本語, 招待, 記事・総説・解説・論説等（学術雑誌） - 【細胞多様性解明に資する光技術-見て,動かす】狙ったものを動かす 光によるショウジョウバエ中枢回路の機能解剖
能瀬 聡直; 高坂 洋史; 伏木 彬
神経活動を"見て,動かす"光技術を脳神経回路の理解につなげるためには,光操作・測定を個々の神経細胞種にピンポイントに適用し,更に,得られた知見を回路の構造に照らして考察する必要がある。本稿では,最近の技術革新により,このような解析が可能となりつつあるショウジョウバエ幼虫(以下"幼虫")を用いた研究について概説する。特に,細胞種特異的Gal4系統のコレクションやコネクトミクス解析などの技術進展について解説し,このような技術を用いて運動制御の回路メカニズムを明らかにした筆者らの研究を紹介したい。(著者抄録), (公財)金原一郎記念医学医療振興財団, 出版日 2017年10月, 生体の科学, 68巻, 5号, 掲載ページ 478-479, 日本語, 0370-9531, 1883-5503, 2018017215 - Dissecting neural network with visible light and genetics
Hiroshi Kohsaka; Akinao Nose
GENETICS SOC JAPAN, 出版日 2013年12月, GENES & GENETIC SYSTEMS, 88巻, 6号, 掲載ページ 339-339, 英語, 研究発表ペーパー・要旨（国際会議）, 1341-7568, 1880-5779, WOS:000337552900033 - ショウジョウバエを用いたオプトジェネティクス研究（分担執筆）
高坂洋史; 能瀬聡直
出版日 2013年, オプトジェネティクス, 掲載ページ 141-153, 日本語, 記事・総説・解説・論説等（学術雑誌） - Formation and plastic change of the terminals of sensory feedback neurons involved in Drosophila larval locomotion
Satoko Okusawa; Hiroshi Kohsaka; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2011年, NEUROSCIENCE RESEARCH, 71巻, 掲載ページ E234-E234, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000308218101265 - Search for interneurons that regulate larval locomotion in Drosophila
Yuki Itakura; Hiroshi Kohsaka; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2011年, NEUROSCIENCE RESEARCH, 71巻, 掲載ページ E245-E245, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000308218101314 - Identification of segmentally-arrayed interneurons that regulate larval locomotion in Drosophila
Hiroshi Kohsaka; Etsuko Takasu; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2011年, NEUROSCIENCE RESEARCH, 71巻, 掲載ページ E100-E100, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000308218100425 - Imaging activity propagation in the larval motor circuits that regulate peristalsis
Hiroshi Kohsaka; Rie Nii; Yoshiaki Nakagawa; Kengo Inada; Akinao Nose
INFORMA HEALTHCARE, 出版日 2010年12月, JOURNAL OF NEUROGENETICS, 24巻, 掲載ページ 43-43, 英語, 研究発表ペーパー・要旨（国際会議）, 0167-7063, WOS:000284537500112 - Temporal perturbation of neural activity in Drosophila larvae undergoing locomotion
Kengo Inada; Hiroshi Kohsaka; Etsuko Takasu; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2010年, NEUROSCIENCE RESEARCH, 68巻, 掲載ページ E435-E435, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000208443703081 - Functional localization of neuronal components controlling larval peristaltic movements in Drosophila
Yoshiaki Nakagawa; Hiroshi Kohsaka; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2010年, NEUROSCIENCE RESEARCH, 68巻, 掲載ページ E444-E444, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000208443703121 - Imaging activity propagation in the Drosophila motor circuits that regulate larval peristalsis
Akinao Nose; Hiroshi Kohsaka; Rie Nii; Yoshiaki Nakagawa; Kengo Inada
ELSEVIER IRELAND LTD, 出版日 2010年, NEUROSCIENCE RESEARCH, 68巻, 掲載ページ E25-E25, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000208443700115 - 研究ニュース
高坂 洋史; 能瀬 聡直
お互いに相手を探り合ってつながる神経回路, 東京大学大学院理学系研究科・理学部, 出版日 2009年05月, 東京大学理学系研究科・理学部ニュース, 41巻, 1号, 掲載ページ 11-11, 日本語, 120001507412, AA11719620 - Formation and plasticity of motor circuits in Drosophila
Akinao Nose; Hiroshi Kohsaka; Yukari Tachi; Satoko Okusawa
ELSEVIER IRELAND LTD, 出版日 2009年, NEUROSCIENCE RESEARCH, 65巻, 掲載ページ S7-S7, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000272421100042 - Imaging of activity propagation in the nerve cord of Drosophila larvae
Hiroshi Kohsaka; Rie Nii; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2009年, NEUROSCIENCE RESEARCH, 65巻, 掲載ページ S200-S201, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000272421101460 - Dynamisms of postsynaptic filopodia during target recognition of Drosophila Neuromuscular Junction
Hiroshi Kohsaka; Akinao Nose
TAYLOR & FRANCIS LTD, 出版日 2009年, JOURNAL OF NEUROGENETICS, 23巻, 掲載ページ S41-S41, 英語, 研究発表ペーパー・要旨（国際会議）, 0167-7063, WOS:000263555500120 - 【神経回路の制御と脳機能発現のメカニズム 細胞移動・接着から記憶・学習・行動発現までの分子基盤解明と研究を躍進させる最新技術】神経回路研究に利用される技術 シナプス形成過程の生体内可視化
高坂 洋史; 能瀬 聡直
シナプスを構成する分子がこれまでに数多く同定され、シナプス構造を分子レベルで描けるようになりつつある。動物の発生過程でシナプス構造が作りあげられる際、これらの分子はシナプス部に組織化されていくと考えられる。ところが、生体内でのシナプス形成過程において分子の分布がどのように制御され、構造化されるかに関しては、ほとんど明らかになっていない。本稿ではショウジョウバエ胚神経筋結合の生体内シナプス可視化について紹介し、この研究から明らかになった生体内シナプスでの細胞接着分子による分子集積機構について述べる。(著者抄録), (株)羊土社, 出版日 2008年07月, 実験医学, 26巻, 12号, 掲載ページ 1985-1992, 日本語, 0288-5514, 2008261822 - Dynamics of postsynaptic filopodia in target recognition of Drosophila neuromuscular synaptogenesis
Hiroshi Kohsaka; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2008年, NEUROSCIENCE RESEARCH, 61巻, 掲載ページ S88-S88, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000261548100526 - Postsynaptic accumulation of cell adhesion molecules imaged in vivo
Hiroshi Kohsaka; Etsuko Takasu; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2007年, NEUROSCIENCE RESEARCH, 58巻, 掲載ページ S206-S206, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000249272801221 - Initial molecular steps in synaptogenesis in vivo: trans-synaptic interaction of cell adhesion molecule is involved in postsynaptic assembly of PSD95-homolog Dlg
Hiroshi Kohsaka; Etsuko Takasu; Akinao Nose
ELSEVIER IRELAND LTD, 出版日 2006年, NEUROSCIENCE RESEARCH, 55巻, 掲載ページ S74-S74, 英語, 研究発表ペーパー・要旨（国際会議）, 0168-0102, WOS:000238609700401 - 【脳の発生分化と回路形成】神経筋連絡の特異性を制御する分子機構
能瀬 聡直; 高坂 洋史
(株)医学書院, 出版日 2005年02月, 神経研究の進歩, 49巻, 1号, 掲載ページ 85-93, 日本語, 0001-8724, 1882-1243, 2005106113 - 神経筋シナプス形成過程における標的認識分子の動態観察 (日本顕微鏡学会第48回シンポジウム 材料科学と生命科学のクロストーク--顕微解析の最前線) -- (生物系セッション2 分子可視化技術による神経細胞の機能解析)
高坂 洋史; 能瀬 聡直
日本顕微鏡学会, 出版日 2003年, 電子顕微鏡, 38巻, 掲載ページ 39-42, 日本語, 0417-0326, 40006067724, AN00145000
書籍等出版物
講演・口頭発表等
- A higher-order interneuron that orchestrates intersegmental coordination in axial locomotion
Takaki Seki; Hiroshi Kohsaka; Akinao Nose
ポスター発表, 英語, Neuroscience 2024, the 53rd Annual Meeting of the Society for Neuroscience (SfN), 査読付
発表日 2024年10月
開催期間 2024年10月05日- 2024年10月09日 - Interspecific comparison of fly larval movement
Hiroshi Kohsaka
口頭発表（招待・特別）, 英語, The 16th Japanese Drosophila Research Conference, 招待
発表日 2024年09月19日
開催期間 2024年09月17日- 2024年09月19日 - 超音波による音響放射圧を用いたショウジョウバエ幼虫への適応的遠隔行動介入
Hiroshi Kohsaka; Xu Zhang; Gakuto Arakawa; Akinao Nose; Masahiro Fujiwara; Yasutoshi Makino
口頭発表（一般）, 英語, 第47回日本神経科学大会, 査読付
発表日 2024年07月27日
開催期間 2024年07月24日- 2024年07月27日 - ショウジョウバエ幼虫における持続的活動を示す神経細胞による運動出力のゲート制御
Takahisa Date; Yingtao Liu; Akihiro Yamaguchi; Rui Wu; Paul McNulty; Marc Gershow; Maarten Zwar; Akinao Nose; Hiroshi Kohsaka
口頭発表（一般）, 英語, 第47回日本神経科学大会, 査読付
発表日 2024年07月26日
開催期間 2024年07月24日- 2024年07月27日 - 軸性運動においてセグメント間協調を指揮する高次介在ニューロン
Takaki Seki; Hiroshi Kohsaka; Akinao Nose
口頭発表（一般）, 英語, 第47回日本神経科学大会, 査読付
発表日 2024年07月26日
開催期間 2024年07月24日- 2024年07月27日 - Transient suppression of tonically active neurons gates motor output in Drosophila larval crawling
Date T; Liu Y; Yamaguchi A; Wu R; McNulty P; Gershow M; Zwart M. F; Nose A; Kohsaka H
ポスター発表, 英語, APDNC3 (ASIA-PACIFIC DROSOPHILA NEUROBIOLOGY CONFERENCE), 査読付
開催期間 2024年02月27日- 2024年03月01日 - Identification of a novel interneuron that regulates forward wave propagation in Drosophila larvae
Seki T; Kohsaka H; Nose A
ポスター発表, 英語, APDNC3 (ASIA-PACIFIC DROSOPHILA NEUROBIOLOGY CONFERENCE), 査読付
開催期間 2024年02月27日- 2024年03月01日 - A tonically active neuron implicated in the maintenance of muscle relaxation in Drosophila larvae
Date T; Liu Y; Nose A; Kohsaka H
口頭発表（一般）, 英語, Cold Spring Harbor laboratory, meeting on Neurobiology of Drosophila, 査読付
発表日 2023年10月
開催期間 2023年10月03日- 2023年10月07日 - Neural circuits and mechanics for crawling in fruit fly larvae
Kohsaka H
口頭発表（招待・特別）, 英語, 日本動物学会 第94回山形大会, 招待
発表日 2023年09月
開催期間 2023年09月07日- 2023年09月09日 - Two perpendicular stripe-wise structures in the neuropil involved in generation of Drosophila larval crawling behaviors
Fukumasu K; Nose A; Kohsaka H
口頭発表（一般）, 英語, 第46回日本神経科学大会, 査読付
発表日 2023年08月
開催期間 2023年08月01日- 2023年08月04日 - Revealing behavior-specific neuronal populations in Drosophila larvae with a photoconvertible calcium sensor
Date T; Nose A; Kohsaka H
ポスター発表, 英語, 第46回日本神経科学大会, 査読付
発表日 2023年08月
開催期間 2023年08月01日- 2023年08月04日 - Mechanisms of neural circuit reorganization that enable coordinated movement
Seki T; Komanome Y; Zeng X; Kohsaka H; Nose A
ポスター発表, 英語, 第46回日本神経科学大会, 査読付
発表日 2023年08月
開催期間 2023年08月01日- 2023年08月04日 - Spatiotemporal structure of synapse population activity in the motor circuits for crawling
Fukumasu K; Nose A; Kohsaka H
口頭発表（招待・特別）, 英語, 第75回日本細胞生物学会大会, 招待
発表日 2023年06月
開催期間 2023年06月28日- 2023年06月30日 - Synchronous multi-segmental activity between metachronal waves controls the crawling speed in fly larvae
Liu Y; Nose A; Zwart M.F; Kohsaka H
第45回日本分子生物学会年会, 招待
発表日 2022年11月30日
開催期間 2022年11月30日- 2022年12月02日 - Synchronous multi-segmental activity controls the speed of axial locomotion by modulating the interval between peristaltic waves in Drosophila larvae
Liu Y; Nose A; Zwart M.F; Kohsaka H
ポスター発表, 英語, Neuroscience 2022, 51st Annual Meeting of the Society for Neuroscience, 査読付
発表日 2022年11月 - Autonomous learning of technical vocabulary used in computer and information science for Japanese university students
Hiroshi Kohsaka
口頭発表（一般）, 英語, CUE ESP Symposium 2022, 査読付
発表日 2022年10月22日 - Automated real-time quantitative analysis of behavior in Drosophila larvae
Zhang X; Nose A; Kohsaka H
ポスター発表, 英語, 第15 回日本ショウジョウバエ研究会 (JDRC15), 査読付
発表日 2022年09月 - Comprehensive characterization of the axon bundles in the Drosophila larval motor circuits with expansion microscopy
Date T; Nose A; Kohsaka H
口頭発表（一般）, 英語, 第15 回日本ショウジョウバエ研究会 (JDRC15), 査読付
発表日 2022年09月 - RNAi-based screening of neuromodulators involved in motor patterns of foraging behavior in Drosophila larvae
Aoki A; Zhang X; Nose A; Kohsaka H
ポスター発表, 英語, 第45回日本神経科学大会 (NEURO2022), 査読付
発表日 2022年06月 - Automated real-time quantitative analysis of behavior in Drosophila larvae
Zhang X; Nose A; Kohsaka H
ポスター発表, 英語, 第45回日本神経科学大会 (NEURO2022), 査読付
発表日 2022年06月 - Module structures in spatial distribution of activity timing and transmitters of synapse population in motor generating circuits
Fukumasu K; Nose A; Kohsaka H
口頭発表（一般）, 英語, 第45回日本神経科学大会 (NEURO2022), 査読付
発表日 2022年06月 - ショウジョウバエ近縁種における幼虫運動制御の種間比較
松尾悠司; 真中美穂; 福益一司; 能瀬聡直; 高坂洋史
シンポジウム・ワークショップパネル（指名）, 日本語, 日本遺伝学会 第93回大会, 招待
発表日 2021年09月 - Dissecting the central nervous system in Drosophila larvae with expansion microscopy
Date T; Nose A; Kohsaka H
口頭発表（一般）, 英語, 第14 回日本ショウジョウバエ研究会(JDRC14), 査読付
発表日 2021年09月 - Spatial configuration of synapse population activities underlying the generation of larval motor patterns
Fukumasu K; Nose A; Kohsaka H
口頭発表（一般）, 英語, 第14 回日本ショウジョウバエ研究会(JDRC14), 査読付
発表日 2021年09月 - Quantitative analysis of Drosophila larval locomotion based on machine vision
Zhang X; Awasaki T; Nose A; Kohsaka H
口頭発表（一般）, 英語, 第44回日本神経科学大会, 査読付
発表日 2021年07月
担当経験のある科目_授業
- Technical English － Basic English for Science
2024年04月 - 現在
電気通信大学 - 物理学実験・エレクトロニクス
東京大学理学部物理学科 - 複雑生命現象論
東京大学大学院新領域創成科学研究科 - 非線形システム解析論
東京大学大学院新領域創成科学研究科 - 実験概論
東京大学大学院新領域創成科学研究科 - Neural circuits
Graduate School of Frontier Science, the University of Tokyo - 神経回路学
東京大学大学院新領域創成科学研究科 - Graduate Technical English
The University of Electro-Communications - 大学院技術英語
電気通信大学 - Academic English for the Second Year I
The University of Electro-Communications - Academic English for the Second Year I
電気通信大学 - Academic Written English I
The University of Electro-Communications - Academic Written English I
電気通信大学 - 英語演習
The University of Electro-Communications - 英語演習
電気通信大学 - Academic English for the Second Year II
The University of Electro-Communications - Academic English for the Second Year II
電気通信大学 - Academic Spoken English II
The University of Electro-Communications - Academic Spoken English II
電気通信大学 - Academic Written English II
The University of Electro-Communications - Academic Written English II
電気通信大学
共同研究・競争的資金等の研究課題
- 遠隔触覚刺激・二次元通信を用いた行動介入基盤の開発と行動予測に基づく動作解析
牧野 泰才
研究期間 2021年09月10日 - 2026年03月31日 - In toto イメージングによる運動制御神経回路の構築過程の解明
高坂 洋史
日本学術振興会, 科学研究費助成事業, 電気通信大学, 基盤研究(C), 23K05959
研究期間 2023年04月 - 2026年03月 - スムーズな筋収縮パターンを生み出す運動制御神経回路機構の解明
高坂 洋史
日本学術振興会, 科学研究費助成事業, 基盤研究(C), 体軸方向に体節構造を持つ動物が、どのように体節間を協調させてスムーズな動きを生み出すのかについて明らかにすることを目指して、ショウジョウバエ幼虫の運動制御システムをモデルとして研究を行なっている。前年度に、前進運動時に強く活動する新規介在神経細胞YT1を同定した。今年度はこの細胞を起点として、神経回路の同定及びその機能解析を進めた。各神経分節に数百個ある神経細胞には、その発生系譜に則って名前が付されているが、形態的特徴や位置情報から、YT1細胞がA31c細胞であることが明らかになった。この知見をもとに、コネクトミクス解析を行なったところ、A31c細胞の下流には主要な細胞としてA26f細胞があり、A26fは体壁筋のうち輪状筋を支配する運動神経細胞を神経支配していることが分かった。そこで、前進運動が駆動する際の輪状筋の収縮パターンを遺伝学的な蛍光ラベルを用いて行なった。前進運動は筋収縮が尾端体節から頭端体節にむけてに伝播する時間とその合間の時間から構成されるのだが、輪状筋はこの伝播波と伝播波の間で、全体節で同期して収縮することが明らかになった。そして、興味深いことに、A31c細胞やA26f細胞の神経活動を操作することで、この輪状筋の収縮及び、前進運動の速度が変化することが明らかになった。このことは、体軸上を筋収縮を伝播させて運動する動物が、伝播波と伝播波の間の時間に輪状筋を同期的に収縮させて時間差を調整することで、運動速度の調節を行なうという新しい運動制御機構を示唆する。, 20K06908
研究期間 2020年04月 - 2023年03月 - 同一の神経回路網が相異なる運動出力を生み出すネットワーク機構の解明
高坂洋史
文部科学省, 科学研究費補助金(基盤研究(C)), 研究代表者
研究期間 2017年04月 - 2020年03月 - 時空間パターンを生み出すメゾ回路の作動原理の解明
能瀬 聡直; 森本 高子; 高坂 洋史
日本学術振興会, 科学研究費助成事業, 東京大学, 新学術領域研究(研究領域提案型), 神経活動の時空間パターンが生成される仕組みを明らかにすることは脳科学における最重要課題のひとつである。本研究では、ショウジョウバエ幼虫の中枢神経回路をモデル系としてこの問題に取り組み以下の成果をあげた。１）運動回路の摂動応答測定により、運動神経細胞の局所的な活動が電気シナプスを介して運動頻度の制御に関与することを示した。２）カルシウムイメージング、光遺伝学、シナプス間隙GFP再構成法、コネクトミクスなどを用いた解析により、幼虫の運動の速度や方向転換を制御する介在神経細胞の機能を示した。３）4Dカルシウムイメージングのデータから細胞集団の活動を自動取得し、統計解析する手法を開発した。, 22115002
研究期間 2010年04月01日 - 2016年03月31日 - 環境に適応した運動出力を生み出す神経回路機構の解明
高坂 洋史
文部科学省, 科学研究費補助金(基盤研究(C)), 東京大学, 基盤研究(C), 研究代表者, 動物の運動速度制御は、動物が環境に適応して行動するために重要である。本研究では、ショウジョウバエ幼虫の運動をモデル系として、運動速度を制御する介在神経細胞を同定し、速度が生み出される回路機構を明らかにした。PMSIsと名付けた細胞により、運動する速さの機構が明らかになった。prePMSI1とprePMSI2という介在神経細胞の同定により、運動の方向性がどのように神経回路に実装されているのかが明らかになった。これらの知見は運動出力を生み出す神経回路機構の一端を明らかにするものとなった。, 26430004
研究期間 2014年 - 2016年 - 運動出力の時空間パターンを生み出す神経回路基盤の解明
高坂洋史
文部科学省, 科学研究費補助金(若手研究(B)), 東京大学, 若手研究(B), 研究代表者, 動物が適切な速さで動くというのは、一見あたりまえのように思われるが、神経回路がどのようにそれを実現しているのかは、ほとんど明らかになっていない。本研究では、神経回路の詳細な解析が可能であるショウジョウバエ幼虫の運動回路をモデルとして、運動の速さを制御する神経回路機構の解明を進めた。その結果、per-IN という一群の神経細胞が運動速度の制御に必要であり、この神経細胞群は、運動神経の活動時間幅を短くすることで、適切な移動速度を生み出していることを見出した。, 24700395
研究期間 2012年 - 2013年 - 局所神経回路形成による運動機能獲得過程の解明
高坂洋史
文部科学省, 科学研究費補助金(若手研究(B)), 東京大学, 若手研究(B), 研究代表者, ショウジョウバエ胚・幼虫の蠕動運動をモデルとして、運動回路の機能発達機構の研究を行った。本年度は、回路の構成要素として、感覚神経細胞と介在神経細胞に注目した。まず、胚・幼虫の蠕動運動制御に関与することが知られているMD感覚神経細胞においてRNA干渉法を用いることで様々な遺伝子の発現を抑制し、運動に与える影響を調べた。その結果、感覚神経細胞におけるタンパク質分解系が、運動機能成熟に関与している結果を得た。さらに、感覚神経細胞の中枢内投射の形態を詳しく調べたところ、正常な投射パターンの形成にタンパク質分解系の機能が必要であることが見いだされた。この結果は、運動回路の構造と機能を正常に発達させるには、タンパク質分解系の制御が必要であることを示唆し、回路発達機構の解明へ向けて重要な要素の同定に至ったと考えられる。一方、運動制御に関与する介在神経細胞を同定するために、カルシウムイメージング法を用いてga14系統のスクリーニングを行なった。その結果、中枢神経内の少数(体節あたり約20個)の神経細胞に発現し、蠕動運動パターンに類似した伝播活動パターンを示すga14系統の同定に成功した。splitGFPを用いた解析によりこれらの介在神経細胞が、運動神経細胞を直接支配していることが示唆された。さらに、温度感受性ダイナミンタンパク質を用いて、この介在神経細胞の活動を抑制したところ、蠕動運動の速度..., 21700344
研究期間 2009年 - 2011年 - 特異的シナプス形成過程に関与する分子の同定と動態観察
能瀬聡直; 高須悦子; 高坂洋史; 高須悦子; 高坂洋史; 森本高子; 稲木美紀子
文部科学省, 科学研究費補助金(特定領域研究), 東京大学, 特定領域研究, 連携研究者, 神経回路は神経細胞が標的の神経細胞や筋肉細胞とシナプスと呼ばれる接着構造を介してつながることで構築されている。神経細胞は特定の標的細胞を認識し、それとのみシナプス結合を形成することにより、特定の機能を生み出す回路を形成する。本研究においては、高度な遺伝子操作が可能なショウジョウバエの神経系をモデルとし、シナプス結合の特異性の決定に関わる新たな機構を解明するとともに、動物個体内で進行するシナプス形成過程の可視化に成功した。, 17024010
研究期間 2005年 - 2009年 - ショウジョウバエ神経筋結合系を用いたシナプス形成初期過程の解析
高坂 洋史
日本学術振興会, 科学研究費助成事業, 東京大学, 特別研究員奨励費, 神経回路網において、細胞と細胞はシナプスという接着構造を介して情報のやりとりをしている。シナプスの形成、維持には、シナプス前細胞、後細胞それぞれに発現する細胞接着分子による接着が重要であると考えられている。この知見は培養細胞(in vitro)を用いた研究から得られたのだが、実際に生体内(in vivo)でシナプス形成がどのように進むかについては、不明である。本研究課題では、ショウジョウバエ神経筋結合系を用いてin vivoでのシナプス形成過程の可視化を行った。また、シナプス後細胞で発現していることが知られている、細胞接着分子ファシクリン2(Fas2)と分子局在を担う蛋白質ディスクスラージ(Dlg)のin vivoでの分布を蛍光タンパク質YFPとの融合タンパク質を用いて解析した。Fas2-YFP,Dlg-YFPはともに成長円錐と筋肉細胞が接触する時期に後シナプス部に局在した。Fas2-YFPは、fas2欠失体においてシナプス部に局在せず、さらにFas2の細胞外領域がシナプス部への集積に十分であったことから、前細胞のFas2がシナプス後細胞のFas2の集積を引き起こすことが強く示唆された。また、fas2機能欠失胚においてDlg-YFPの局在および、グルタミン酸受容体の分布に異常がみられた。これらの結果は、シナプス形成過程において、前細胞のFas2が接着を介して後細胞のFas2の集積を誘導し、さらにDlgやグルタミン酸受容体などのシナプス構造に重要な分子の分布を制御することを示唆する。これまでin vivoでのシナプス形成初期過程の研究は困難であったが、本研究はin vivoでの接着分子の役割を初めて解明するものとなった。, 04J11006
研究期間 2004年 - 2005年
社会貢献活動
メディア報道
- 電通大と東大、ハエの幼虫において運動と運動の間の静止時に特定の筋が収縮していることを発見
日本経済新聞・電子版, インターネットメディア
公開日 2023年08月08日 - 虫のような軟らかいロボット、電通大ら開発 電子回路など微細環境での作業の応用期待
Yahoo! JAPAN ニュース, インターネットメディア
公開日 2023年04月13日 - 電通大と東大、しなやかな幼虫の動きを再現するソフトロボットの開発に成功
日本経済新聞・電子版, インターネットメディア
公開日 2023年04月06日 - Extraction of bouton-like structures from neuropil calcium imaging data
本人, AAAS (American Association for the Advancement of Science), EurekAlert!, インターネットメディア
公開日 2022年11月 - Relationship between the speed at which insects move and the environmental temperature
本人, UEC e-Bulletin, インターネットメディア
公開日 2021年09月28日
