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Gotou T, Kameyama K, Kobayashi A, Okamura K, Ando T, Terata K, Yamada C, Ohta H, Morizane A, Hata Y. Dark Rearing Promotes the Recovery of Visual Cortical Responses but Not the Morphology of Geniculocortical Axons in Amblyopic Cat. Front Neural Circuits 2021; 15:637638. [PMID: 33935657 PMCID: PMC8085520 DOI: 10.3389/fncir.2021.637638] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 03/23/2021] [Indexed: 11/13/2022] Open
Abstract
Monocular deprivation (MD) of vision during early postnatal life induces amblyopia, and most neurons in the primary visual cortex lose their responses to the closed eye. Anatomically, the somata of neurons in the closed-eye recipient layer of the lateral geniculate nucleus (LGN) shrink and their axons projecting to the visual cortex retract. Although it has been difficult to restore visual acuity after maturation, recent studies in rodents and cats showed that a period of exposure to complete darkness could promote recovery from amblyopia induced by prior MD. However, in cats, which have an organization of central visual pathways similar to humans, the effect of dark rearing only improves monocular vision and does not restore binocular depth perception. To determine whether dark rearing can completely restore the visual pathway, we examined its effect on the three major concomitants of MD in individual visual neurons, eye preference of visual cortical neurons and soma size and axon morphology of LGN neurons. Dark rearing improved the recovery of visual cortical responses to the closed eye compared with the recovery under binocular conditions. However, geniculocortical axons serving the closed eye remained retracted after dark rearing, whereas reopening the closed eye restored the soma size of LGN neurons. These results indicate that dark rearing incompletely restores the visual pathway, and thus exerts a limited restorative effect on visual function.
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Affiliation(s)
- Takahiro Gotou
- Division of Integrative Bioscience, Tottori University Graduate School of Medical Sciences, Yonago, Japan
| | - Katsuro Kameyama
- Division of Integrative Bioscience, Tottori University Graduate School of Medical Sciences, Yonago, Japan.,Division of Neuroscience, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Ayane Kobayashi
- Division of Integrative Bioscience, Tottori University Graduate School of Medical Sciences, Yonago, Japan
| | - Kayoko Okamura
- Division of Integrative Bioscience, Tottori University Graduate School of Medical Sciences, Yonago, Japan
| | - Takahiko Ando
- Division of Neuroscience, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Keiko Terata
- Division of Integrative Bioscience, Tottori University Graduate School of Medical Sciences, Yonago, Japan
| | - Chihiro Yamada
- Division of Integrative Bioscience, Tottori University Graduate School of Medical Sciences, Yonago, Japan
| | - Hiroyuki Ohta
- Division of Integrative Bioscience, Tottori University Graduate School of Medical Sciences, Yonago, Japan
| | - Ayaka Morizane
- Division of Neuroscience, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Yoshio Hata
- Division of Integrative Bioscience, Tottori University Graduate School of Medical Sciences, Yonago, Japan.,Division of Neuroscience, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan
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