会聚轴突共同启动并维持在不断重塑的感觉器官中的突触选择性。

Converging axons collectively initiate and maintain synaptic selectivity in a constantly remodeling sensory organ.

机构信息

Unit of Sensory Biology & Organogenesis, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Munich, Germany.

Centre for Genomic Regulation, Dr. Aiguader 88, 08003 Barcelona, Spain.

出版信息

Curr Biol. 2014 Dec 15;24(24):2968-74. doi: 10.1016/j.cub.2014.11.012. Epub 2014 Dec 4.

Abstract

Sensory receptors are the functional link between the environment and the brain. The repair of sensory organs enables animals to continuously detect environmental stimuli. However, receptor cell turnover can affect sensory acuity by changing neural connectivity patterns. In zebrafish, two to four postsynaptic lateralis afferent axons converge into individual peripheral mechanosensory organs called neuromasts, which contain hair cell receptors of opposing planar polarity. Yet, each axon exclusively synapses with hair cells of identical polarity during development and regeneration to transmit unidirectional mechanical signals to the brain. The mechanism that governs this exceptionally accurate and resilient synaptic selectivity remains unknown. We show here that converging axons are mutually dependent for polarity-selective connectivity. If rendered solitary, these axons establish simultaneous functional synapses with hair cells of opposing polarities to transmit bidirectional mechanical signals. Remarkably, nonselectivity by solitary axons can be corrected upon the reintroduction of additional axons. Collectively, our results suggest that lateralis synaptogenesis is intrinsically nonselective and that interaxonal interactions continuously rectify mismatched synapses. This dynamic organization of neural connectivity may represent a general solution to maintain coherent synaptic transmission from sensory organs undergoing frequent variations in the number and spatial distribution of receptor cells.

摘要

感觉受体是环境和大脑之间的功能联系。感觉器官的修复使动物能够不断地检测环境刺激。然而,受体细胞的更替会通过改变神经连接模式而影响感觉敏锐度。在斑马鱼中,两个到四个突触后 lateralis 传入轴突汇聚到单个外周机械感觉器官称为毛细胞感受器,其中包含具有相反平面极性的毛细胞受体。然而,在发育和再生过程中,每个轴突仅与具有相同极性的毛细胞形成突触,以将单向机械信号传递到大脑。支配这种异常精确和有弹性的突触选择性的机制仍然未知。我们在这里表明,汇聚的轴突彼此依赖于极性选择性连接。如果使这些轴突孤立,它们会与具有相反极性的毛细胞同时建立功能性突触,以传递双向机械信号。值得注意的是,单个轴突的非选择性可以通过引入额外的轴突来纠正。总之,我们的结果表明 lateralis 突触发生是内在非选择性的,并且轴间相互作用不断纠正不匹配的突触。这种神经网络连接的动态组织可能代表了一种通用的解决方案,用于维持来自感觉器官的连贯的突触传递,这些感觉器官的受体细胞数量和空间分布经常发生变化。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索