Long‐Term Tracking and Dynamically Quantifying of Reversible Changes of Extracellular Ca2+ in Multiple Brain Regions of Freely Moving Animals

• Published in: Angewandte Chemie International Edition 2021-06, Vol.60 (26), p.14429-14437
• Main Authors: Liu, Yuandong, Liu, Zhichao, Zhao, Fan, Tian, Yang
• Format: Article
• Language: English
• Subjects: anti-biofouling; Biofouling; Brain; Calcium (extracellular); Calcium influx; Calcium ions; Cell death; Ischemia; microfiber arrays; Microfibers; Reperfusion; reversibility; Spatial discrimination; Spatial resolution; Stroke; Tracking
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202102833

Understanding physiological and pathological processes in the brain requires tracking the reversible changes in chemical signals with long‐term stability. We developed a new anti‐biofouling microfiber array to real‐time quantify extracellular Ca2+ concentrations together with neuron activity across many regions in the mammalian brain for 60 days, in which the signal degradation was < ca. 8 %. The microarray with high tempo‐spatial resolution (ca. 10 μm, ca. 1.3 s) was implanted into 7 brain regions of free‐moving mice to monitor reversible changes of extracellular Ca2+ upon ischemia‐reperfusion processes. The changing sequence and rate of Ca2+ in 7 brain regions were different during the stroke. ROS scavenger could protect Ca2+ influx and neuronal activity after stroke, suggesting the significant influence of ROS on Ca2+ overload and neuron death. We demonstrated this microarray is a versatile tool for investigating brain dynamic during pathological processes and drug treatment. An anti‐biofouling microfiber array was created to real‐time tracking and reversibly quantifying of extracellular concentration of Ca2+ together with neuron activity across many regions in freely moving mammalian brain for 60 days. The changing sequence and rate of Ca2+ in 7 brain regions were different during the stroke, and ROS scavenger could protect Ca2+ influx and neuronal activity after stroke.