霍华德休斯医学院Kaspar Podgorski课题组在研究中取得进展。他们揭示了谷氨酸盐指标具有更高的敏感性和定制的失活率。该研究于2025年12月23日发表于国际一流学术期刊《自然—方法学》杂志上。

在这里，该研究团队开发了两个高度敏感的第五代iGluSnFR变体，具有快速激活和定制的失活率：iGluSnFR4f用于跟踪快速动态，iGluSnFR4s用于记录大量突触。这些指标在体内具有较高的空间特异性和单囊敏感性。研究人员对它们进行了主题化，以记录小鼠在多种实验环境下突触传递的自然模式，包括皮质层1-4和海马CA1的双光子成像，以及中脑的光度测定。iGluSnFR4变体扩展了谷氨酸成像的速度、灵敏度和可扩展性，从而能够直接观察完整大脑中通过神经网络的信息流。

研究人员表示，了解神经元如何整合来自输入突触的信号需要同时监测多个部位的神经传递的方法。荧光蛋白谷氨酸指示剂iGluSnFR可以实现突触信号的可视化，但这种测量的灵敏度、规模和速度受到现有变体的限制。

附：英文原文

Title: Glutamate indicators with increased sensitivity and tailored deactivation rates

Author: Aggarwal, Abhi, Negrean, Adrian, Chen, Yang, Iyer, Rishyashring, Reep, Daniel, Liu, Anyi, Palutla, Anirudh, Xie, Michael E., MacLennan, Bryan J., Hagihara, Kenta M., Kinsey, Lucas W., Sun, Julianna L., Yao, Pantong, Zheng, Jihong, Tsang, Arthur, Tsegaye, Getahun, Zhang, Yonghai, Patel, Ronak H., Arthur, Benjamin J., Hiblot, Julien, Leippe, Philipp, Tarnawski, Miroslaw, Marvin, Jonathan S., Vevea, Jason D., Turaga, Srinivas C., Tebo, Alison G., Carandini, Matteo, Rossi, L. Federico, Kleinfeld, David, Konnerth, Arthur, Svoboda, Karel, Turner, Glenn C., Hasseman, Jeremy P., Podgorski, Kaspar

Issue&Volume: 2025-12-23

Abstract: Understanding how neurons integrate signals from thousands of input synapses requires methods to monitor neurotransmission across many sites simultaneously. The fluorescent protein glutamate indicator iGluSnFR enables visualization of synaptic signaling, but the sensitivity, scale and speed of such measurements are limited by existing variants. Here we developed two highly sensitive fourth-generation iGluSnFR variants with fast activation and tailored deactivation rates: iGluSnFR4f for tracking rapid dynamics, and iGluSnFR4s for recording from large populations of synapses. These indicators detect glutamate with high spatial specificity and single-vesicle sensitivity in vivo. We used them to record natural patterns of synaptic transmission across multiple experimental contexts in mice, including two-photon imaging in cortical layers 1–4 and hippocampal CA1, and photometry in the midbrain. The iGluSnFR4 variants extend the speed, sensitivity and scalability of glutamate imaging, enabling direct observation of information flow through neural networks in the intact brain.

DOI: 10.1038/s41592-025-02965-z

Source: https://www.nature.com/articles/s41592-025-02965-z