ゼブラフィッシュの視覚に関する脳回路は、網膜からの入力なしに発達する。 Brain circuits for vision develop without any kind of input from the retina in zebrafish
2023-09-27 マックス・プランク研究所
◆通常、視覚情報が脳の神経回路形成に不可欠と考えられていますが、研究では視覚情報を脳に伝える網膜神経細胞の変異を持つゼブラフィッシュを用いて、この仮説を挑戦しました。その結果、変異体の脳は正常に発達し、視覚に関連する行動も適切に実行できることが示され、視覚情報がない状況でも脳回路が機能することが示唆されました。
<関連情報>
- https://www.mpg.de/20891945/0927-psy-vision-in-the-brain-hardwired-for-action-155111-x
- https://www.nature.com/articles/s41467-023-40749-1
網膜由来のシグナルは視覚脳領域の神経新生のペースを制御するが、回路の組み立ては制御しない Retina-derived signals control pace of neurogenesis in visual brain areas but not circuit assembly
Shachar Sherman,Irene Arnold-Ammer,Martin W. Schneider,Koichi Kawakami & Herwig Baier
Nature Communications Published:27 September 2023
DOI:https://doi.org/10.1038/s41467-023-40749-1
Abstract
Brain development is orchestrated by both innate and experience-dependent mechanisms, but their relative contributions are difficult to disentangle. Here we asked if and how central visual areas are altered in a vertebrate brain depleted of any and all signals from retinal ganglion cells throughout development. We transcriptionally profiled neurons in pretectum, thalamus and other retinorecipient areas of larval zebrafish and searched for changes in lakritz mutants that lack all retinal connections. Although individual genes are dysregulated, the complete set of 77 neuronal types develops in apparently normal proportions, at normal locations, and along normal differentiation trajectories. Strikingly, the cell-cycle exits of proliferating progenitors in these areas are delayed, and a greater fraction of early postmitotic precursors remain uncommitted or are diverted to a pre-glial fate. Optogenetic stimulation targeting groups of neurons normally involved in processing visual information evokes behaviors indistinguishable from wildtype. In conclusion, we show that signals emitted by retinal axons influence the pace of neurogenesis in visual brain areas, but do not detectably affect the specification or wiring of downstream neurons.
