成人脳での急速な眼優位性可塑性を駆動する二重メカニズムを解明(Study Reveals Dual Mechanisms Driving Rapid Ocular Dominance Plasticity in Adult Brain)

ad

2025-11-14 中国科学院(CAS)

中国科学院生物物理研究所と温州医科大学の共同研究チームは、成人人脳における眼優位性可塑性(ocular dominance plasticity)が、短時間の片眼遮断だけで急速に変化する仕組みを、相反しつつ補完的な2つのメカニズムとして解明した。成人被験者に3時間の片眼コントラスト遮断を行い、7T fMRIで観察したところ、遮断された眼では外側膝状体(LGN)傍細胞層と視床枕(pulvinar)領域の活動増強とともにコントラスト感度が上昇。一方、非遮断眼では3D形状知覚の向上と、立体視に関わる視覚皮質の活動増大が見られた。さらに、pulvinar と大脳皮質の可塑性変化は負の相関を示し、サブコルチカルとコルチカルの両経路が互いに補い合いつつ視覚入力の不均衡に適応していることが判明。本成果は、弱視(amblyopia)など視覚障害の新たな治療法開発に重要な示唆を与える。

成人脳での急速な眼優位性可塑性を駆動する二重メカニズムを解明(Study Reveals Dual Mechanisms Driving Rapid Ocular Dominance Plasticity in Adult Brain)
Two opposing but complementary mechanisms of ocular dominance plasticity in the visual thalamus and cortex (Image by ZHANG Peng’s group)

<関連情報>

相反しながらも補完的な2つの眼優位性可塑性:視床は弱いチャネルを強化し、高次皮質は強い信号を聴く Two opposing yet complementary ocular dominance plasticities: thalamus strengthens the weak channel while higher cortex listens to the strong signal

Yazhu Qian,Zhouyuan Sun,Yizhi Wang,Yige Gao,Chencan Qian,Jiawei Zhou & Peng Zhang
Communications Biology  Published:11 November 2025
DOI:https://doi.org/10.1038/s42003-025-08914-y

Abstract

Neural mechanisms of ocular dominance plasticity in the adult brain remain elusive. Using high-resolution functional magnetic resonance imaging (fMRI) at 7 T, we investigated ocular dominance plasticity in the visual thalamus and extrastriate visual cortices in response to monocular contrast deprivation (MCD) in human adults. Short-term (3 hours) MCD enhanced the sensitivity of the deprived eye (DE) relative to the non-deprived eye (NDE) in the lateral geniculate nucleus and the ventrolateral pulvinar of the thalamus. Compared to the NDE, the DE became more sensitive in contrast detection and more dominant in binocular combination. On the other hand, MCD reduced DE relative to NDE sensitivity in extrastriate cortices, and DE relative to NDE performance in 3-D shape perception. These findings demonstrate that a homeostatic mechanism in the visual thalamus concurrently operates with a Hebbian-like mechanism in extrastriate cortices to rapidly and adaptively adjust interocular balance to disrupted binocular input.

医療・健康
ad
ad
Follow
ad
タイトルとURLをコピーしました