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

Abstract

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.

Novel Self-Calibrating Amperometric and Ratiometric Electrochemical Nanotip Microsensor for pH Measurement in Rat Brain

“…It is important to verify that the pH response is not influenced by protein adsorption, which is abundant in rat brains or whole blood, , so the anti-biofouling ability of the present biosensor was examined. Here, albumin from bovine serum albumin (BSA), which acts as a model molecule, was studied with the same experimental procedures in this work.…”

Raman Fiber Photometry for Understanding Mitochondrial Superoxide Burst and Extracellular Calcium Ion Influx upon Acute Hypoxia in the Brain of Freely Moving Animals

“…[2c] However, in the neurons, no significant changes were observed in size and frequency of mitochondrial CaPP during hypoxia (Figure 4i). On the other hand, extracellular Ca 2 + was simultaneously measured by using our previously developed method, [6] it was observed that extracellular Ca 2 + was decreased from 1.24 � 0.06 mM to 0.58 � 0.05 mM in hippocampus of WT mice brain upon acute hypoxia for 60 min, while that of Ca 2 + mito was increased by � 0.27 mM. Meanwhile, extracellular Ca 2 + was decreased only by � 0.06 mM in that of ASIC1a À /À mice (Figure 4j).…”

“…[5] Recently, we developed an electrochemophysiological microarray with excellent anti-pollution performance for real-time mapping and quantification of ion signals in the deep brain of a freely moving mouse. [6] Fluorescence imaging combined with fiber photometry and modern genetic tools, have revolutionized neuroscience by recording of intracellular molecular signals in living animals. [7] To date, most of these fluorescent approaches study brain activity mainly by recording the changes of Ca 2 + signal, [8] simultaneously recording of different neurochemical signals is still challenging due to the broad fluorescence peaks.…”

Electrochemical aptamer-based biosensors for &lt;italic&gt;in vivo&lt;/italic&gt; analysis

“…3.1 体外分析 生理活性分子, 如小分子 [68,27] 、核酸 [69,70] 、蛋白 质 [71,72] 等在生命活动过程中扮演着重要的角色, 其 选择性分析对于了解生命活动过程的化学本质具有 重要意义. 近些年来, 利用核酸适体电化学传感器实 现了体外及细胞层次生理活性分子定性和定量分析 [73][74][75] .…”