Optimization of Ace2N based voltage indicators

Genetically encoded voltage indicators (GEVIs) are routinely used to image neuronal activity and they underlie many recent advances in cellular functional imaging. However, many sensors still have major limitations when used in vivo. Ace2N based voltage indicators, developed at different labs including Janelia, represents a class of GEVIs that’s sensitive (from spike detection to subthreshold membrane potential reporting), fast (submillisecond level for recently published ASAP2f variant) and other advantages depending on the fluorophore used. GENIE project engineers and optimizes a series of GEVIs including Ace2N based voltage indicators. With our high-throughput neuronal culture screening and patch clamp assay platform, we identified multiple single and combo mutations that dramatically improve the sensitivity to voltage change.

基因编码电压指示剂（Genetically Encoded Voltage Indicators, GEVIs）是当前用于神经元活动成像的常规工具，亦是近年来细胞功能成像领域多项突破的核心支撑。然而，多数此类传感器在活体应用中仍存在显著局限。由包括Janelia在内的多个实验室开发的基于Ace2N的电压指示剂，属于一类兼具电压敏感性（可实现动作电位尖峰检测与阈下膜电位记录）与快速响应特性（最新发表的ASAP2f变体可达亚毫秒级响应速度）的GEVIs，其额外性能优势取决于所选用的荧光基团。GENIE项目的工程师团队对包括基于Ace2N的电压指示剂在内的多款GEVIs开展了开发与优化工作。依托高通量神经元培养筛选与膜片钳检测平台，我们筛选到多个单突变体与组合突变体，可显著提升传感器对电压变化的敏感性。