用于在神经元群体和微区中成像活性的高性能钙传感器。

High-performance calcium sensors for imaging activity in neuronal populations and microcompartments.

机构信息

Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.

Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.

出版信息

Nat Methods. 2019 Jul;16(7):649-657. doi: 10.1038/s41592-019-0435-6. Epub 2019 Jun 17.

DOI:10.1038/s41592-019-0435-6

PMID:31209382

Abstract

Calcium imaging with genetically encoded calcium indicators (GECIs) is routinely used to measure neural activity in intact nervous systems. GECIs are frequently used in one of two different modes: to track activity in large populations of neuronal cell bodies, or to follow dynamics in subcellular compartments such as axons, dendrites and individual synaptic compartments. Despite major advances, calcium imaging is still limited by the biophysical properties of existing GECIs, including affinity, signal-to-noise ratio, rise and decay kinetics and dynamic range. Using structure-guided mutagenesis and neuron-based screening, we optimized the green fluorescent protein-based GECI GCaMP6 for different modes of in vivo imaging. The resulting jGCaMP7 sensors provide improved detection of individual spikes (jGCaMP7s,f), imaging in neurites and neuropil (jGCaMP7b), and may allow tracking larger populations of neurons using two-photon (jGCaMP7s,f) or wide-field (jGCaMP7c) imaging.

摘要

利用基因编码钙指示剂（GECIs）进行钙成像，已被常规用于测量完整神经系统中的神经活动。GECIs 通常以两种不同模式之一使用：一种是追踪大量神经元胞体的活动，另一种是跟踪轴突、树突和单个突触隔室等亚细胞隔室中的动态。尽管取得了重大进展，但钙成像仍然受到现有 GECIs 的生物物理特性的限制，包括亲和力、信噪比、上升和下降动力学以及动态范围。通过结构引导的突变和基于神经元的筛选，我们优化了基于绿色荧光蛋白的 GECI GCaMP6，以适应不同的体内成像模式。由此产生的 jGCaMP7 传感器提供了对单个尖峰的检测（jGCaMP7s,f）、神经突和神经胶成像（jGCaMP7b）的改善，并且可能允许使用双光子（jGCaMP7s,f）或宽场（jGCaMP7c）成像来跟踪更多的神经元群体。