Hironobu Sakaguchi, Nozomu Saito,
Song learning in the male zebra finch closely correlates with the development of song-control nuclei, the high vocal center (HVc), the robust nucleus of the archistriatum (RA) and the lateral magnocellular nucleus of the anterior neostriatum (IMAN). We previously found that acetylcholine (ACh) content increases transiently in the RA during the sensitive period of song learning. In the present experiment, development of cholinergic neurons by immunohistochemical methods using monoclonal choline acetyltransferase ( ...
Tópico(s): Primate Behavior and Ecology
1991 - Elsevier BV | Developmental Brain Research
Hironobu Sakaguchi, Nozomu Saito,
The acetylcholine (ACh), dopamine (DA) and noradrenaline (NA) concentrations in the song control nuclei, the magnocellular nucleus of the anterior neostriatum (MAN), the caudal nucleus of the ventral hyperstriatum (HVc) and the robust nucleus of the archistriatum (RA) were measured using high performance liquid chromatography (HPLC) at 5 different ages (30, 40, 50, 60 and 90 days after hatching). ACh concentration of these nuclei increased markedly during the critical period for learning and decreased gradually ...
Tópico(s): Marine animal studies overview
1989 - Elsevier BV | Developmental Brain Research
Hironobu Sakaguchi, Masao Asano, Katsunobu Yamamoto, Nozomu Saito,
The release of γ-aminobutyric acid (GABA) from the robust nucleus of the archistriatum (RA) of the zebra finch was examined in slice preparations. Potassium-induced depolarization caused calcium-dependent release of GABA. GABA release by veratrine was blocked by tetrodotoxin. Electrical stimulation of fibers dorsal to RA also released GABA. There was no sex difference in GABA release per wet weight of RA, while the size of the female RA is smaller than that of the male RA.
Tópico(s): Bat Biology and Ecology Studies
1987 - Elsevier BV | Brain Research
Michinori Kubota, Hironobu Sakaguchi, Nakaakira Tsukahara,
The release of endogenous gamma-aminobutyric acid (GABA) from the cat red nucleus was studied in a slice preparation. Potassium-induced depolarization caused a release of GABA in a calcium-dependent manner. The release of GABA was also induced by veratrine and blocked by tetrodotoxin. The demonstration of release satisfies one of the important criteria for identification of GABA as the inhibitory neurotransmitter.
Tópico(s): GABA and Rice Research
1983 - Elsevier BV | Brain Research
Hironobu Sakaguchi, Kozo Iwasa,
Phototaxis of Volvox carteri is the result of two photophobic responses: stop and accelerationof flagellar activity in the anterior region of the colony. These responses of a colony fixed under a microscope were analyzed quantitatively by cine-micrography. The phototactic sign of Volvox is temperature-dependent: it is positive at room temperature and negative at low temperature. When the temperature was lowered, the stop response to the on-stimulus was reduced and changed to the acceleration response, ...
Tópico(s): Neurobiology and Insect Physiology Research
1979 - Oxford University Press | Plant and Cell Physiology
The sign of phototaxis in Volvox carteri is temperature-dependent; positive at room temperature and negative at low temperature. Modification of the tactic sign by external ions, pH and chemicals was studied. The addition of 30 mM potassium ion to the medium changed the tactic sign from positive to negative, and a medium with a high pH elicited positive phototaxis. An increase in the potassium or hydrogen ion concentration raised the reversal temperature of the phototactic sign, and the addition ...
Tópico(s): Mass Spectrometry Techniques and Applications
1979 - Oxford University Press | Plant and Cell Physiology
Hironobu Sakaguchi, Katsuhisa Tawada,
SYNOPSIS. The effect of temperature on photoaccumulation and photophobic response of Volvox aureus were studied. The algae exhibited positive photoaccumulation at room temperature and negative at low temperature. When stimulated with light of intermediate intensiy (∼ 5 × 10 3 lux), the phobic response of the algae consisted of a decrease in the frequency or the cessation of flagellar movement in the anterior cells. At room temperature, an increase in light intensity elicited the phobic response, whereas ...
Tópico(s): Biocrusts and Microbial Ecology
1977 - Wiley | The Journal of Protozoology
Hironobu Sakaguchi, Yuta Uetake, Masato Ohashi, Takashi Niwa, Sensuke Ogoshi, Takamitsu Hosoya,
Monodefluoroborylation of polyfluoroalkenes has been achieved in a regioselective manner under mild conditions via copper catalysis. The method has shown an extremely broad scope of substrates, including (difluorovinyl)arenes, tetrafluoroethylene (TFE), (trifluorovinyl)arenes, and trifluoromethylated monofluoroalkenes. The choice of boron source was important for the efficient transformation of (difluorovinyl)arenes; (Bpin)2 was suitable for substrates with an electron-deficient aryl group and (Bnep)2 ...
Tópico(s): Carbon dioxide utilization in catalysis
2017 - American Chemical Society | Journal of the American Chemical Society
Richard Hetherington, Rachel McRae,
... analysis were: Final Fantasy: The Spirits Within (dir. Hironobu Sakaguchi and Motonori Sakakibara, 2001), The Polar Express (dir. ...
Tópico(s): Human Motion and Animation
2017 - SAGE Publishing | Animation
Hironobu Sakaguchi, Masato Ohashi, Sensuke Ogoshi,
Abstract Herein, a copper‐catalyzed C−F bond defluorosilylation reaction of tetrafluoroethylene and other polyfluoroalkenes is described. Mechanistic studies, based on a series of stoichiometric reactions with copper complexes, revealed that the key steps of this defluorosilylation reaction are 1) the 1,2‐addition of a silylcopper intermediate to the polyfluoroalkene and 2) a subsequent selective β‐fluorine elimination, which generates a Cu−F species. The β‐fluorine elimination is facilitated by ...
Tópico(s): Carbon dioxide utilization in catalysis
2017 - Wiley | Angewandte Chemie
Hironobu Sakaguchi, Masato Ohashi, Sensuke Ogoshi,
Herein, a copper-catalyzed C-F bond defluorosilylation reaction of tetrafluoroethylene and other polyfluoroalkenes is described. Mechanistic studies, based on a series of stoichiometric reactions with copper complexes, revealed that the key steps of this defluorosilylation reaction are 1) the 1,2-addition of a silylcopper intermediate to the polyfluoroalkene and 2) a subsequent selective β-fluorine elimination, which generates a Cu-F species. The β-fluorine elimination is facilitated by Lewis acidic ...
Tópico(s): Inorganic Fluorides and Related Compounds
2017 - Wiley | Angewandte Chemie International Edition
Kotaro Kikushima, Hironobu Sakaguchi, Hiroki Saijo, Masato Ohashi, Sensuke Ogoshi,
Abstract We developed the copper-mediated synthesis of trifluorostyrene derivatives. β-Fluorine elimination of a 2-aryl-1,1,2,2-tetrafluoroethylcopper complex, generated in situ from arylboronate, copper tert-butoxide, and 1,10-phenanthroline with tetrafluoroethylene (TFE) via carbocupration, was promoted by the addition of a Lewis acid. The present reaction system was applied to the one-pot synthesis of various trifluorostyrene derivatives, through the transmetalation–carbocupration–β-fluorine elimination ...
Tópico(s): Chemical Synthesis and Analysis
2015 - Oxford University Press | Chemistry Letters
Yusuke Kita, Hironobu Sakaguchi, Yoichi Hoshimoto, Daisuke Nakauchi, Yasuhito Nakahara, Jean‐François Carpentier, Sensuke Ogoshi, Kazushi Mashima,
Abstract Direct amination of allylic alcohols with primary and secondary amines catalyzed by a system made of [Ni(1,5‐cyclooctadiene) 2 ] and 1,1′‐bis(diphenylphosphino)ferrocene was effectively enhanced by adding n Bu 4 NOAc and molecular sieves, affording the corresponding allyl amines in high yield with high monoallylation selectivity for primary amines and high regioselectivity for monosubstituted allylic alcohols. Such remarkable additive effects of n Bu 4 NOAc were elucidated by isolating and ...
Tópico(s): Asymmetric Synthesis and Catalysis
2015 - Wiley | Chemistry - A European Journal
Hiroki Saijo, Hironobu Sakaguchi, Masato Ohashi, Sensuke Ogoshi,
A Pd(0)-catalyzed Hiyama coupling reaction of tetrafluoroethylene (TFE) proceeded without the use of a base to give α,β,β-trifluorostyrene derivatives. A Ni(0)-catalyzed Hiyama coupling reaction of perfluoroarenes also occurred without a base. The key intermediate in these reactions would be a transition-metal fluoride complex that is generated in situ by the oxidative addition of a C–F bond.
Tópico(s): Catalytic C–H Functionalization Methods
2014 - American Chemical Society | Organometallics
... Rintaro, 2001), and Final Fantasy: The Spirits Within (Hironobu Sakaguchi and Motonori Sakakibara, 2001) engage utopian daydreams and ...
Tópico(s): Digital Games and Media
2013 - SAGE Publishing | Animation
Masayuki Matsumoto, Hironobu Sakaguchi,
An experiment of an all-optical DPSK-signal regeneration is reported. In the regenerator, incoming DPSK signals are first demodulated to on-off-keying signals, then amplitude-regenerated by a 2R regenerator, and subsequently used as control pulses for phase remodulation of clock pulses in an all-optical phase modulator. Penalty-free operation with reduced amplitude noise is demonstrated by the use of a two-stage fiberbased cascaded 2R amplitude regenerator in bidirectional configuration.
Tópico(s): Advanced Photonic Communication Systems
2008 - Optica Publishing Group | Optics Express
Masayuki Matsumoto, Yoshiyuki Shimada, Hironobu Sakaguchi,
Two-stage all-optical 2R (reamplification and reshaping) signal regeneration based on spectrum broadening due to self-phase modulation in a nonlinear fiber and subsequent off-centered filtering is demonstrated by the use of only one fiber spool in which the signal is transmitted twice in opposite directions. The two-stage configuration allows wavelength shift-free operation of the regenerator. Recirculating-loop signal transmission and regeneration experiment shows that the bidirectional 2R regenerator ...
Tópico(s): Advanced Photonic Communication Systems
2008 - IEEE Photonics Society | IEEE Journal of Quantum Electronics
Aiko Watanabe, Rui Li, Takeji Kimura, Hironobu Sakaguchi,
Abstract We investigated the participation of protein kinase C (PKC) in the regulation of vocal plasticity in songbirds. Deafening of adult Bengalese finches causes initial song alteration, followed by stabilization. In parallel, the expression of PKC β1 increases transiently 2 weeks after deafening, and then decreases gradually in the robust nucleus of the arcopallium (RA) of Bengalese finches, similar to the pattern observed during developmental song learning. First, we showed that in adult zebra ...
Tópico(s): Marine animal studies overview
2006 - Wiley | European Journal of Neuroscience
Kazuhiro Wada, Jason T. Howard, Patrick McConnell, Osceola Whitney, Thierry Lints, Miriam V. Rivas, Haruhito Horita, Michael Patterson, Stephanie A. White, Constance Scharff, Sebastian Haesler, Shengli Zhao, Hironobu Sakaguchi, Masatoshi Hagiwara, Toshiyuki Shiraki, Tomoko Hirozane-Kishikawa, J. H. Pate Skene, Yoshihide Hayashizaki, Piero Carninci, Erich D. Jarvis,
Songbirds have one of the most accessible neural systems for the study of brain mechanisms of behavior. However, neuroethological studies in songbirds have been limited by the lack of high-throughput molecular resources and gene-manipulation tools. To overcome these limitations, we constructed 21 regular, normalized, and subtracted full-length cDNA libraries from brains of zebra finches in 57 developmental and behavioral conditions in an attempt to clone as much of the brain transcriptome as possible. ...
Tópico(s): Marine animal studies overview
2006 - National Academy of Sciences | Proceedings of the National Academy of Sciences
... cursed grey shadows’ (1896), while recent reviewers of Hironobu Sakaguchi’s Final Fantasy: The Spirits Within (2001) have ...
Tópico(s): Digital Games and Media
2006 - SAGE Publishing | Animation
Kazuhiro Wada, Hironobu Sakaguchi, Erich D. Jarvis, Masatoshi Hagiwara,
Abstract Learned vocalization, the substrate for human language, is a rare trait. It is found in three distantly related groups of birds—parrots, hummingbirds, and songbirds. These three groups contain cerebral vocal nuclei for learned vocalization not found in their more closely related vocal nonlearning relatives. Here, we cloned 21 receptor subunits/subtypes of all four glutamate receptor families (AMPA, kainate, NMDA, and metabotropic) and examined their expression in vocal nuclei of songbirds. ...
Tópico(s): Marine animal studies overview
2004 - Wiley | The Journal of Comparative Neurology
Aiko Watanabe, Takeji Kimura, Hironobu Sakaguchi,
Auditory feedback is necessary to maintain singing in the adult male Bengalese finch (songbirds/oscines). Their song patterns are altered within a month following cochlear removal-induced deafness. Stabilization of song patterns occurs thereafter. To clarify what kind of changes appear in the brain of deafened birds, we examined immunohistochemically the expression of protein kinase C (PKC), considered a molecular marker for synaptic plasticity, in the robust nucleus of the archistriatum (RA), one ...
Tópico(s): Marine animal studies overview
2002 - Lippincott Williams & Wilkins | Neuroreport
Hironobu Sakaguchi, Rui Li, Ikuo Taniguchi,
The two main song control nuclei in the forebrain of zebra finches, the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA), are sexually dimorphic at many levels of their neural circuitry. These nuclei receive their cholinergic innervation from the ventral paleostriatum (VP), which is homologous to portions of the mammalian basal forebrain. We compared the cholinergic neurons in the VP between the sexes using choline acetyltransferase (ChAT) immunohistochemistry. Both the size ...
Tópico(s): Marine animal studies overview
2000 - Lippincott Williams & Wilkins | Neuroreport
Rui Li, Mingxue Zuo, Hironobu Sakaguchi,
THE two main song control nuclei in the zebra finch forebrain, the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA), receive cholinergic innervation from the ventral paleostriatum (VP) of the basal forebrain which may play a key role in song learning. By injecting two kinds of neuroanatomical tracers, we found that a topographically segregated pathway from nucleus ovoidalis (Ov) and nucleus dorsomedialis posterior thalami (DMP) to VP and further to RA and HVC. Ov is known as ...
Tópico(s): Marine animal studies overview
1999 - Lippincott Williams & Wilkins | Neuroreport
Hironobu Sakaguchi, Kazuhiro Wada, Masao Maekawa, Toshikazu Watsuji, Masatoshi Hagiwara,
We have investigated the participation of cAMP response element-binding protein (CREB) in the response of the songbird brain to a natural auditory stimulus, a conspecific song. The cells in the two song control nuclei, the higher vocal center (HVC) and area X of zebra finches (Taeniopygia guttata), were intensely stained with an anti-CREB monoclonal antibody. Double-labeling studies showed that CREB immunoreactivity was detected only in area X-projecting neurons in the HVC. The cloned CREB cDNA from ...
Tópico(s): Animal Behavior and Reproduction
1999 - Society for Neuroscience | Journal of Neuroscience
Jian Wang, Hironobu Sakaguchi, Masahiro Sokabe,
MALE zebra finches sing, whereas female zebra finches do not. To elucidate the neural mechanisms underlying sexual dimorphism in song behavior, the spatio-temporal properties of neural activity in the vocal motor pathway of the zebra finch were examined in sliced brain preparations using a real-time optical recording technique. Electrical stimulation to higher vocal center (HVC) fibers induced within 20 ms neural activities in the robust nucleus of the archistriatum (RA) of both male and female finches, ...
Tópico(s): Marine animal studies overview
1999 - Lippincott Williams & Wilkins | Neuroreport
Hironobu Sakaguchi, Ayako Yamaguchi,
Male zebra finches learn to imitate a tutor's song through auditory and motor learning during a sensitive period. The molecular aspects of auditory-dependent learning was investigated using protein kinase C (PKC) as a molecular marker for synaptic plasticity. We found a transient increase in the expression of PKC in the robust nucleus of the archistriatum (RA) during a sensitive period. Furthermore, both early deafening by cochlea removal and song deprivation inhibited the increase of PKC enzyme activity. ...
Tópico(s): Marine animal studies overview
1997 - Lippincott Williams & Wilkins | Neuroreport
During the sensitive period of song learning, the content of acetylcholine and the enzyme activity of choline acetyltransferase (ChAT) increase remarkably in the song control nuclei of a young male zebra finch. Cholinergic fibers innervate the two main song control nuclei of the forebrain: the higher vocal center (HVC) and the robust nucleus of the archistriatum (RA). The present study combines the retrograde tracer, Fluoro-Red (FRe), with ChAT immunohistochemistry. The results indicate that the cholinergic ...
Tópico(s): Marine animal studies overview
1997 - Elsevier BV | Brain Research
Tópico(s): Marine animal studies overview
1996 - Springer Science+Business Media | Experimental Brain Research
Hironobu Sakaguchi, Nozomu Saito,
Tópico(s): Bat Biology and Ecology Studies
1996 - Elsevier BV | Developmental Brain Research