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178 results on '"Yoshimatsu, Takeshi"'

5. α2δ-4 Is Required for the Molecular and Structural Organization of Rod and Cone Photoreceptor Synapses.

Author

Kerov, Vasily, Laird, Joseph, Joiner, Mei-Ling, Knecht, Sharmon, Soh, Daniel, Hagen, Jussara, Gardner, Sarah, Gutierrez, Wade, Yoshimatsu, Takeshi, Bhattarai, Sajag, Artemyev, Nikolai, Drack, Arlene, Wong, Rachel, Baker, Sheila, Lee, Amy, and Puthussery, Teresa

Subjects
Ca2+ channel, photoreceptor, retina, ribbon synapse, synaptogenesis, Animals, Calcium Channels, L-Type, Female, Humans, Macaca fascicularis, Male, Mice, Mice, Knockout, Photoreceptor Cells, Vertebrate, Synapses
Abstract

α2δ-4 is an auxiliary subunit of voltage-gated Cav1.4 L-type channels that regulate the development and mature exocytotic function of the photoreceptor ribbon synapse. In humans, mutations in the CACNA2D4 gene encoding α2δ-4 cause heterogeneous forms of vision impairment in humans, the underlying pathogenic mechanisms of which remain unclear. To investigate the retinal function of α2δ-4, we used genome editing to generate an α2δ-4 knock-out (α2δ-4 KO) mouse. In male and female α2δ-4 KO mice, rod spherules lack ribbons and other synaptic hallmarks early in development. Although the molecular organization of cone synapses is less affected than rod synapses, horizontal and cone bipolar processes extend abnormally in the outer nuclear layer in α2δ-4 KO retina. In reconstructions of α2δ-4 KO cone pedicles by serial block face scanning electron microscopy, ribbons appear normal, except that less than one-third show the expected triadic organization of processes at ribbon sites. The severity of the synaptic defects in α2δ-4 KO mice correlates with a progressive loss of Cav1.4 channels, first in terminals of rods and later cones. Despite the absence of b-waves in electroretinograms, visually guided behavior is evident in α2δ-4 KO mice and better under photopic than scotopic conditions. We conclude that α2δ-4 plays an essential role in maintaining the structural and functional integrity of rod and cone synapses, the disruption of which may contribute to visual impairment in humans with CACNA2D4 mutations.SIGNIFICANCE STATEMENT In the retina, visual information is first communicated by the synapse formed between photoreceptors and second-order neurons. The mechanisms that regulate the structural integrity of this synapse are poorly understood. Here we demonstrate a role for α2δ-4, a subunit of voltage-gated Ca2+ channels, in organizing the structure and function of photoreceptor synapses. We find that presynaptic Ca2+ channels are progressively lost and that rod and cone synapses are disrupted in mice that lack α2δ-4. Our results suggest that alterations in presynaptic Ca2+ signaling and photoreceptor synapse structure may contribute to vision impairment in humans with mutations in the CACNA2D4 gene encoding α2δ-4.

Published
2018

10. Setting up a state‐of‐the‐art laboratory in resource limited settings: A case study of the biomedical science research and training centre in Northeast Nigeria

Author

Isah, Murtala Bindawa, primary, Muhammad, Zaid, additional, Lawan, Mohammed Musa, additional, Alkhamis, Abdulrahman Idris, additional, Goni, Baba Waru, additional, Oakley, Sebastian Scott, additional, Marshall, Karen, additional, Hartig, Renée, additional, Raouf, Issa Sabi‐Abdoul, additional, Yoshimatsu, Takeshi, additional, Chagas, André Maia, additional, and Maina, Mahmoud Bukar, additional

Published
2024
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15. Setting Up A State-Of-The-Art Laboratory In Resource Limited Settings: A Case Study Of The Biomedical Science Research And Training Centre In Northeast Nigeria

Author

Isah, Murtala, primary, Muhammad, Zaid, additional, Lawan, Mohammed, additional, Alkhamis, Abdulrahman, additional, Goni, Baba, additional, Oakley, Sebastian, additional, Marshall, Karen, additional, Hartig, Renee, additional, Issa, Abdul-Raouf, additional, Yoshimatsu, Takeshi, additional, Chagas, André, additional, and Maina, Mahmoud, additional

Published
2023
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16. Ancient origin of the rod bipolar cell pathway in the vertebrate retina

Author

Hellevik, Ayana M, primary, Mardoum, Philip, additional, Hahn, Joshua, additional, Kölsch, Yvonne, additional, D’Orazi, Florence D, additional, Suzuki, Sachihiro C., additional, Godinho, Leanne, additional, Lawrence, Owen, additional, Rieke, Fred, additional, Shekhar, Karthik, additional, Sanes, Joshua R, additional, Baier, Herwig, additional, Baden, Tom, additional, Wong, Rachel O, additional, and Yoshimatsu, Takeshi, additional

Published
2023
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17. Simple models for neuroscience research discoveries: how often are these models used in Africa?

Author

Hamidu, Suleiman Kwairanga, primary, Umar, Ahmad, additional, Abdulazeez, Rashidat, additional, Muhammad, Zaid, additional, Alkhamis, Abdulrahman Idris, additional, Umar, Mohammed, additional, Ladan, Ahmad Aliyu, additional, Nasr, Fayza Eid, additional, Ahmad, Aisha, additional, Musa, Sunday Abraham, additional, Ya'u, Jamilu, additional, Hamman, Wilson Oliver, additional, Isah, Murtala Bindawa, additional, Bello, Sanusi Muhammad, additional, Yoshimatsu, Takeshi, additional, Issa, Sabi Raouf, additional, and Bukar Maina, Mahmoud, additional

Published
2023
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29. Stimulation of functional neuronal regeneration from Mller glia in adult mice

Author

Jorstad, Nikolas L., Wilken, Matthew S., Grimes, William N., Wohl, Stefanie G., VandenBosch, Leah S., Yoshimatsu, Takeshi, Wong, Rachel O., Rieke, Fred, and Reh, Thomas A.

Subjects
Care and treatment, Physiological aspects, Methods, Neurogenesis -- Methods, Nerve regeneration -- Methods, Retinal diseases -- Care and treatment, Retinal ganglion cells -- Physiological aspects
Abstract

Author(s): Nikolas L. Jorstad [1, 2]; Matthew S. Wilken [1]; William N. Grimes [3]; Stefanie G. Wohl [1]; Leah S. VandenBosch [1]; Takeshi Yoshimatsu [1]; Rachel O. Wong [1]; Fred [...]

Published
2017
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32. A High-Density Narrow-Field Inhibitory Retinal Interneuron with Direct Coupling to Müller Glia

Author

Grimes, William N., primary, Aytürk, Didem Göz, additional, Hoon, Mrinalini, additional, Yoshimatsu, Takeshi, additional, Gamlin, Clare, additional, Carrera, Daniel, additional, Nath, Amurta, additional, Nadal-Nicolás, Francisco M., additional, Ahlquist, Richard M., additional, Sabnis, Adit, additional, Berson, David M., additional, Diamond, Jeffrey S., additional, Wong, Rachel O., additional, Cepko, Connie, additional, and Rieke, Fred, additional

Published
2021
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34. Notch promotes survival of neural precursor cells via mechanisms distinct from those regulating neurogenesis

Author

Oishi, Koji, Kamakura, Sachiko, Isazawa, Yuko, Yoshimatsu, Takeshi, Kuida, Keisuke, Nakafuku, Masato, Masuyama, Norihisa, and Gotoh, Yukiko

Subjects
Proteins -- Research, Cells -- Research, Brain -- Research, Biological sciences
Abstract

During development of the mammalian brain, many neural precursor cells (NPCs) undergo apoptosis. The regulation of such cell death, however, is poorly understood. We now show that the survival of mouse embryonic NPCs in vitro was increased by culture at a high cell density and that this effect was attributable to activation of Notch signaling. Expression of an active form of Notch1 thus markedly promoted NPC survival. Hes proteins, key effectors of Notch signaling in inhibition of neurogenesis, were not sufficient for the survival-promoting effect of Notch1. This effect of Notch1 required a region of the protein containing the RAM domain and was accompanied by up-regulation of the anti-apoptotic proteins Bc1-2 and Mc1-1. Moreover, knockdown of these proteins by RAM interference resulted in blockade of the Notch1-induced survival. These results reveal a new function of Notch, the promotion of NPC survival. Keywords: Notch: Hes; Neural Precursor Cell; Survival; Caspase; Bc1-2; Signaling

Published
2004

40. Spherical arena reveals optokinetic response tuning to stimulus location, size and frequency across entire visual field of larval zebrafish

Author

Dehmelt, Florian A., Meier, Rebecca, Hinz, Julian, Yoshimatsu, Takeshi, Simacek, Clara A., Wang, Kun, Baden, Tom, and Arrenberg, Aristides B.

Subjects
genetic structures, eye diseases
Abstract

Many animals have large visual fields, allowing them to observe almost any stimulus in their surround. The underlying sensory circuits have evolved to sample those visual field regions most informative to the animal. These regions can vary between different visually mediated behaviours, such as stabilisation and hunting behaviour. Despite this, relatively small displays are often used in vision neuroscience, making it difficult to study the tuning of the visual system to specific visual field locations. To overcome these technical limitations and reveal the organisation of motion circuits with respect to visual space, we built a spherical stimulus arena with 14,848 independently controllable LEDs and used it to stimulate almost the entire visual surround of immobilised zebrafish larvae. We measured the gain of the optokinetic response at different stimulus positions relative to the fish, and related behavioural performance to photoreceptor densities in the retina. We report that zebrafish larvae react most strongly and consistently to stimuli located laterally and near the equator of their visual space. The OKR appears to be symmetric between both eyes, although individual animals oftentimes have a dominant eye. For small stimuli, the OKR gain depends on stimulus size in a logarithmic fashion. OKR to our mostly green stimuli was tuned to the higher spatial densities of red, green and blue photoreceptors in the central retina. In addition, experiments in animals mounted upside-down suggest that extra-retinal processing affects the preferred OKR stimulus location. The tuning to stimulus size and spatial frequency was similar across different visual field positions. During monocular motion stimulation, the non-stimulated eye was strongly yoked if a low-contrast stimulus was present, and less so if a high-contrast stimulus was presented. Our results provide a precise analysis of OKR responses across the whole visual field, and relate sensory performance both to the architecture of the retina and to downstream neural pathways. Our results suggest that motion vision circuits in zebrafish are highly anisotropic. We hypothesize that they monitor specific positions in visual space that are relevant for behaviour in nature, and specifically, that the observed variation of OKR performance across visual field locations is caused by retinal and central adaptations of the zebrafish brain to behavioural needs during visual orientation and stabilisation. Author summary The visual system of larval zebrafish mirrors many features, present in the visual system of other vertebrates, including its ability to mediate optomotor and optokinetic behaviour. Although the presence of such behaviours and some of the underlying neural correlates have been firmly established, previous experiments did not consider the large visual field of zebrafish, which covers more than 160° for each eye. Given that different parts of the visual field likely carry unequal amount of behaviourally relevant information for the animal, this raises the question whether optic flow is integrated across the entire visual field or just parts of it, and how this shapes behaviour such as the optokinetic response. We constructed a spherical LED arena to present visual stimuli almost anywhere across their visual field, while tracking horizontal eye movements. By displaying moving gratings on this LED arena, we demonstrate that the optokinetic response, one of the most prominent visually induced behaviours of zebrafish, indeed strongly depends on stimulus location and stimulus size, as well as on other parameters such as the spatial and temporal frequency of the gratings. This location dependence is consistent with areas of high retinal photoreceptor densities. Blurb Stimulation across entire visual field reveals that zebrafish optokinetic behaviour is most strongly driven by lateral stimulus locations. This anisotropy is a result of retinal and extra-retinal effects.

Published
2019
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41. A high-density narrow-field inhibitory retinal interneuron with direct coupling to Müller glia

Author

Grimes, William N, primary, Aytürk, Didem Göz, additional, Hoon, Mrinalini, additional, Yoshimatsu, Takeshi, additional, Gamlin, Clare, additional, Carrera, Daniel, additional, Ahlquist, Richard M, additional, Sabnis, Adit, additional, Diamond, Jeffrey S, additional, Wong, Rachel O., additional, Cepko, Connie, additional, and Rieke, Fred, additional

Published
2020
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Author

Kerov, Vasily, Kerov, Vasily, Laird, Joseph G, Joiner, Mei-ling, Knecht, Sharmon, Soh, Daniel, Hagen, Jussara, Gardner, Sarah H, Gutierrez, Wade, Yoshimatsu, Takeshi, Bhattarai, Sajag, Puthussery, Teresa, Artemyev, Nikolai O, Drack, Arlene V, Wong, Rachel O, Baker, Sheila A, Lee, Amy, Kerov, Vasily, Kerov, Vasily, Laird, Joseph G, Joiner, Mei-ling, Knecht, Sharmon, Soh, Daniel, Hagen, Jussara, Gardner, Sarah H, Gutierrez, Wade, Yoshimatsu, Takeshi, Bhattarai, Sajag, Puthussery, Teresa, Artemyev, Nikolai O, Drack, Arlene V, Wong, Rachel O, Baker, Sheila A, and Lee, Amy

Published
2018

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Author

Kerov, Vasily, Kerov, Vasily, Laird, Joseph, Joiner, Mei-Ling, Knecht, Sharmon, Soh, Daniel, Hagen, Jussara, Gardner, Sarah, Gutierrez, Wade, Yoshimatsu, Takeshi, Bhattarai, Sajag, Artemyev, Nikolai, Drack, Arlene, Wong, Rachel, Baker, Sheila, Lee, Amy, Puthussery, Teresa, Kerov, Vasily, Kerov, Vasily, Laird, Joseph, Joiner, Mei-Ling, Knecht, Sharmon, Soh, Daniel, Hagen, Jussara, Gardner, Sarah, Gutierrez, Wade, Yoshimatsu, Takeshi, Bhattarai, Sajag, Artemyev, Nikolai, Drack, Arlene, Wong, Rachel, Baker, Sheila, Lee, Amy, and Puthussery, Teresa

Published
2018

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