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

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 mu m, 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.

Automated summary

Understanding physiological and pathological processes in the brain requires tracking reversible changes in chemical signals with long-term stability. A new anti-biofouling microfiber array was developed to quantify extracellular Ca2+ concentrations and neuron activity in real-time across multiple regions in the mammalian brain for 60 days, providing high tempo-spatial resolution and the ability to monitor reversible changes during ischemia-reperfusion processes. This microarray serves as a versatile tool for investigating brain dynamics during pathological processes and drug treatment, demonstrating the significant influence of ROS on Ca2+ overload and neuron death after stroke.