Highly active neurons emerging in vitro
Highly active neurons emerging in vitro
复制标题
体外出现高度活跃的神经元
DOI：
10.1152/jn.00663.2020
复制
发表时间：
2021
影响因子：
2.5
通讯作者：
Ikegaya Yuji
中科院分区：
文献类型：
--
作者：
Okada Mami;Kono Rena;Sato Yu;Kobayashi Chiaki;Koyama Ryuta;Ikegaya Yuji
在神经元网络中，神经元的平均放电率各不相同。虽然大多数神经元不经常发出尖峰，但一小部分神经元表现出极高的尖峰频率；这部分神经元在信息处理中起着关键作用，然而，很少有人知道这些异常值是如何出现的，以及它们是否会随着时间的推移而保持。在小鼠海马神经元原代培养中，我们通过光学观察荧光蛋白dVenus，每24 h跟踪高活性神经元，持续7周；dVenus的表达是由arc的启动子控制的，arc是一种由神经元活动诱导的即时早期基因。在默认模式条件下，0.3%-0.4%的神经元自发呈Arc-dVenus阳性，表现出高放电率。这些神经元在空间上聚集，表现出间歇性重复的dVenus表达，并经常持续表达Arc-dVenus约2周。因此，高度活跃的神经元在神经元网络中构成了几个精选的功能亚群。神经元活动水平的过度分散通常可以归因于极少数神经元表现出极高的放电率，但由于技术上的困难，没有研究调查这些异常值在发育过程中是如何被选择的，以及它们是否随着时间的推移而保持。我们在体外对高度活跃的神经元进行了长达7周的光学监测，发现它们构成了一个独特的群体，不同于其他具有正常放电率的“平庸”神经元。
Mean firing rates vary across neurons in a neuronal network. Although most neurons infrequently emit spikes, a small fraction of neurons exhibit extremely high frequencies of spikes; this fraction of neurons plays a pivotal role in information processing, however, little is known about how these outliers emerge and whether they are maintained over time. In primary cultures of mouse hippocampal neurons, we traced highly active neurons every 24 h for 7 wk by optically observing the fluorescent protein dVenus; the expression of dVenus was controlled by the promoter ofArc, an immediate early gene that is induced by neuronal activity. Under default-mode conditions, 0.3%–0.4% of neurons were spontaneously Arc-dVenus positive, exhibiting high firing rates. These neurons were spatially clustered, exhibited intermittently repeated dVenus expression, and often continued to express Arc-dVenus for approximately 2 wk. Thus, highly active neurons constitute a few select functional subpopulations in the neuronal network.NEW & NOTEWORTHYThe overdispersion of neuronal activity levels can often be attributed to very few neurons exhibiting extremely high firing rates, but due to technical difficulty, no studies have examined how these outliers are selected during development and whether they are maintained over time. We optically monitored highly active neurons for as long as 7 wk in vitro and found that they constituted a unique population that was different from other “mediocre” neurons with normal firing rates.