Experimental Verification for Numerical Simulation of Thalamic Stimulation-Evoked Calcium-Sensitive Fluorescence and Electrophysiology with Self-Assembled Multifunctional Optrode

Owing to its capacity to eliminate a long-standing methodological limitation, fiber photometry can assist research gaining novel insight into neural systems. Fiber photometry can reveal artifact-free neural activity under deep brain stimulation (DBS). Although evoking neural potential with DBS is an effective method for mediating neural activity and neural function, the relationship between DBS-evoked neural Ca2+ change and DBS-evoked neural electrophysiology remains unknown. Therefore, in this study, a self-assembled optrode was demonstrated as a DBS stimulator and an optical biosensor capable of concurrently recording Ca2+ fluorescence and electrophysiological signals. Before the in vivo experiment, the volume of tissue activated (VTA) was estimated, and the simulated Ca2+ signals were presented using Monte Carlo (MC) simulation to approach the realistic in vivo environment. When VTA and the simulated Ca2+ signals were combined, the distribution of simulated Ca2+ fluorescence signals matched the VTA region. In addition, the in vivo experiment revealed a correlation between the local field potential (LFP) and the Ca2+ fluorescence signal in the evoked region, revealing the relationship between electrophysiology and the performance of neural Ca2+ concentration behavior. Concurrent with the VTA volume, simulated Ca2+ intensity, and the in vivo experiment, these data suggested that the behavior of neural electrophysiology was consistent with the phenomenon of Ca2+ influx to neurons.

Automated summary

Fiber photometry can overcome methodological limitations and provide new insights into neural systems. It can accurately measure neural activity under deep brain stimulation without artifacts. This study demonstrated the use of a self-assembled optrode as a stimulator and biosensor to record both Ca2+ fluorescence and electrophysiological signals, revealing a correlation between local field potential and Ca2+ fluorescence signal in the evoked region.