626 research outputs found
Data_of_Temporal_dynamics_of_the_sensorimotor_convergence_underlying_voluntary_limb_movement
No full textSoftware and dataset used in a manuscript
Inwardly Rectifying and Ca<sup>2+</sup>-Permeable AMPA-Type Glutamate Receptor Channels in Rat Neocortical Neurons
No full text Itazawa, Shun-Ichi, Tadashi Isa, and Seiji Ozawa. Inwardly rectifying and Ca2+-permeable AMPA-type glutamate receptor channels in rat neocortical neurons. J. Neurophysiol. 78: 2592–2605, 1997. Current-voltage ( I-V) relations and Ca2+ permeability of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)type glutamate receptor channels were investigated in neurons of rat neocortex by using the whole cell patch-clamp technique in brain slices. To activate AMPA receptor channels, kainate was used as a nondesensitizing agonist. A patch pipette was filled with solution containing 100 μM spermine to maintain the inward rectification of Ca2+-permeable AMPA receptor channels. Three types of responses to kainate were observed: type I response with outwardly rectifying I-V relation, type II response with I-V relation of marked inward rectification, and intermediate response with I-V relation of weaker inward rectification. Neurons with type I, type II and intermediate I-V relations were referred to as type I, type II, and intermediate neurons, respectively. Of a total of 223 recorded cells, 90 (40.4%) were type I, 129 (57.8%) intermediate, and 4 (1.8%) type II neurons. Properties of AMPA receptor channels were examined in the former two types of neurons. The value of PCa:PCs, the ratio of the permeability coefficients of Ca2+ and Cs+, was estimated from the reversal potentials of kainate responses in the outside-out patches bathed in Na+-free solution containing 100 mM Ca2+ according to the constant-field equation. They ranged from 0.05 to 0.10 (0.08 ± 0.02, mean ± SD, n = 8) for type I neurons and from 0.14 to 1.29 (0.60 ± 0.37, n = 11) for the intermediate neurons. There was a close correlation between the inward rectification and the Ca2+ permeability in AMPA receptor channels in these neurons. Intermediate neurons stained with biocytin were nonpyramidal cells with ellipsoidal-shaped somata. Type I neurons had either triangular- or ellipsoidal-shaped somata. Excitatory postsynaptic currents (EPSCs) recorded in both type I and intermediate neurons had 6-cyano-7-nitroquinoxaline-2,3-dione-sensitive fast and d−2-amino-5-phosphonovalerate-sensitiveslow components. The I-V relation of the fast component exhibited inward rectification in the intermediate neuron, whereas that in the type I neuron showed slight outward rectification. The fast component of EPSCs in the intermediate neuron was suppressed more prominently (to 56 ± 15% of the control, n = 12) than that in the type I neuron (to 78 ± 6% of the control, n = 6) by bath application of 1 mM spermine. These results indicate that inwardly rectifying and Ca2+-permeable AMPA receptor channels are expressed in a population of neurons of rat neocortex and are involved in excitatory synaptic transmission. </jats:p
A common subcortical oscillatory network contributes to recovery after spinal cord injury
No full textRecent studies in monkeys showed that when the direct cortico-motoneuronal connection was transected at mid-cervical segments, remaining, indirect cortico-motoneuronal pathways compensated for finger dexterity within one to three months. To elucidate the changes in dynamic properties of neural circuits during the recovery, we investigated the cortico-muscular and inter-muscular couplings of activities throughout the recovery course. Activities of antagonist muscle pairs showed co-activation during the second postoperative week, and oscillated coherently at frequencies of 30-46 Hz (gamma-band) by one month postoperatively. Such gamma-band inter-muscular coherence was not observed preoperatively, but became prominent and distributed widely over proximal and distal muscles with the recovery. Neither the gamma-band cortico-muscular coupling (14-30 Hz) observed before lesion, nor a gamma-band oscillation was observed in bilateral motor cortex after lesion. Thus, we propose that an unknown, subcortical oscillator, independent of cortical oscillation, commonly recruits hand/arm muscles and may underlie functional recovery of dexterous finger movements
The Superior Colliculus/Tectum: Cell Types, Circuits, Computations, Behaviors
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Letter from M. Kurima to Mr. and Mrs. Okine, January 22, 1946 [in Japanese]
No full textA letter from Tadashi Mac and Fusaye Alice Kurima in Chicago, Illinois, to their relatives, Seiichi and Tomeyo Okine in Hawthorne, California. Kurima thanks them for the Christmas gift and congratulates on their daughter, Hatsuno's marriage. He also writes about Masao Okine who sent a 5-yen bill to Kurima from Japan.The Okine Collection contains materials collected by Seiichi and Tomeyo Okine who were Issei flower growers in Whittier, California. It includes correspondence, photographs, financial documents, and a photo album. A large portion of the collection consists of family correspondence with Seiichi and Tomeyo Okine, including letters from their Nisei children, Masao and Makoto Okine, both soldiers overseas during World War II, to their Issei parents incarcerated in the Rohwer incarceration camp in McGehee, Arkansas. The correspondence also includes letters from their relatives and friends who are former incarcerees in the camps during the war and have “resettled” in Chicago, Illinois as well as letters from the Okines’ family members in Hiroshima, Japan during the Allied occupation of Japan. In addition, the collection includes a family photo album compiled by Dorothy Ai Aoki, a Nisei daughter to the Okines
Chen-Ricci inequalities for Riemannian maps and their applications
No full textAMS Special Session Differential Geometry and Global Analysis, Honoring the Memory of Tadashi Nagano (1930-2017) at Joint Mathematical Meeting -- JAN 16, 2020 -- Denver, CORiemannian maps between Riemannian manifolds, originally introduced by A.E. Fischer in [Contemp. Math. 132 (1992), 331-366], provide an excellent tool for comparing the geometric structures of the source and target manifolds. Isometric immersions and Riemannian submersions are particular examples of such maps. In this work, we first prove a geometric inequality for Riemannian maps having a real space form as a target manifold. Applying it to the particular case of Riemannian submanifolds, we recover a classical result, obtained by B.-Y. Chen in [Glasgow Math. J. 41 (1999), 33-41], which nowadays is known as the Chen-Ricci inequality. Moreover, we extend this inequality in case of Riemannian maps with a complex space form as a target manifold. We also improve this inequality when the Riemannian map is Lagrangian. Applying it to Riemannian submanifolds, we recover the improved Chen-Ricci inequality for Lagrangian submanifolds in a complex space form, that is a basic inequality obtained by S. Deng in [Int. Electron. Electron. J. Geom. 2 (2009), 39-45] as an improvement of a geometric inequality stated by B.-Y. Chen in [Arch. Math. (Basel) 74 (2000), 154-160].Amer Math SocNational Research Foundation of Korea [2019K2A9A1A06097856]; Scientific and Technological Research Council of Turkey (TUBITAK) [119N087]; Basic Science Research Program through the National Research Foundation of Korea (NRF) - Ministry of Education [2018R1D1A1B07040576]; Ministry of Research, Innovation and Digitization, CNCS/CCCDI -UEFISCDI [PN-III-P4-ID-PCE-2020-0025]The first author was supported under the framework of international cooperation program managed by the National Research Foundation of Korea (2019K2A9A1A06097856). The third author was supported under the framework of international cooperation program managed by the Scientific and Technological Research Council of Turkey (TUBITAK) with project id: 119N087. The second author was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2018R1D1A1B07040576). The fourth author was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS/CCCDI -UEFISCDI, project number PN-III-P4-ID-PCE-2020-0025, within PNCDI III
Balancing risk-return decisions by manipulating the mesofrontal circuits in primates
No full textリスクと報酬の意思決定バランスを光で調節 --精神神経疾患などの病態解明に期待--. 京都大学プレスリリース. 2024-01-05.Lighting the Circuits to Risky Decision-Making. 京都大学プレスリリース. 2024-01-05.Decision-making is always coupled with some level of risk, with more pathological forms of risk-taking decisions manifesting as gambling disorders. In macaque monkeys trained in a high risk–high return (HH) versus low risk–low return (LL) choice task, we found that the reversible pharmacological inactivation of ventral Brodmann area 6 (area 6V) impaired the risk dependency of decision-making. Selective optogenetic activation of the mesofrontal pathway from the ventral tegmental area (VTA) to the ventral aspect of 6V resulted in stronger preference for HH, whereas activation of the pathway from the VTA to the dorsal aspect of 6V led to LL preference. Finally, computational decoding captured the modulations of behavioral preference. Our results suggest that VTA inputs to area 6V determine the decision balance between HH and LL
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