Implanted microelectrode arrays for evaluating inhibited seizure modulated by light-responsive hydrogel

Abstract

Microelectrode arrays (MEAs) are crucial tools for evaluating the modulating effects during in vivo neuromodualtion and it is crucial to develop novel strategies that allow for high spatiotemporal resolution, sustainable potential and dynamic monitoring during neurological disease therapy. Herein, we used a hydrogelator to assemble with ruthenium-based light-sensitive compound, RuBi-GABA, to prepare a light-responsive supramolecular hydrogel for suppressing seizures in the cortex of epileptic rats, which benefited the prolonged release of RuBi-GABA. Meanwhile, the real-time variations in neuronal action potentials (Spikes) and local field potentials (LFPs) during the modulation were recorded by nanomaterial-modified implanted MEAs. The results demonstrated the mean firing rate and LFP power sharply decreased 54.95% and 76.56% due to the light-activation of RuBi-GABA hydrogel in a timely manner. Additionally, the high synchronicity between pyramidal neurons and interneurons efficiently decreased after the illumination. Furthermore, simultaneous modulation of spikes and LFPs in time and frequency domain demonstrated that cortical seizures were efficiently inhibited from microscopic to mesoscopic signals. We anticipated that the strategy of using RuBi-GABA hydrogel for seizure control with the simultaneous effectiveness evaluation by the MEAs could lead to a novel approach for epilepsy therapy.

PtNPs/rGO-GluOx/mPD Directionally Electroplated Dual-Mode Microelectrode Arrays for Detecting the Synergistic Relationship between the Cortex and Hippocampus of Epileptic Rats

“…As shown in Figure S1, the proposed IMEA was formed by three masks, including a conducting layer, an insulating layer, and a base layer, in a clean room using MEMS technology, and the fabrication setups of the IMEA have been demonstrated in detail in previous studies. 26,27 Directional Modification of the Glu Site. The cGO-GluOx compounds were prepared as shown in Figure 1A.…”

“…The epileptic rat models were fabricated as the method reported in our previous study. 27 The epileptic rat models were anesthetized and fixed on a stereotaxic frame to achieve accurate positioning. 28 Four craniotomies were carried out including the implantation location for IMEA and the tubing (AP: −3.6 mm, ML: 2.5 mm), the location for optical fiber (AP: −3.6 mm, ML: 4 mm), the location for the Ag|AgCl reference electrode for Glu detection (AP: −1.6 mm, ML: 2.5 mm), and a random site for ground connection, as shown in Figure S3.…”

“…The 16 electrodes of the IMEA contained two diameters of 12 and 17 μm, and the larger ones were designed for Glu detection here, which allowed for loading more nanomaterial-enzyme compounds. As shown in Figure S1, the proposed IMEA was formed by three masks, including a conducting layer, an insulating layer, and a base layer, in a clean room using MEMS technology, and the fabrication setups of the IMEA have been demonstrated in detail in previous studies. , …”

“…We applied pilocarpine-induced epileptic rat models to evaluate the dual-mode detection capability of the modified IMEA in vivo. The epileptic rat models were fabricated as the method reported in our previous study . The epileptic rat models were anesthetized and fixed on a stereotaxic frame to achieve accurate positioning .…”

Grid cell remapping under three-dimensional object and social landmarks detected by implantable microelectrode arrays for the medial entorhinal cortex

“…When the MEA was packaged, we modified the surface of the recording sites with platinum nanoparticles (PtNPs) to reduce the impedance and improve the signal-to-noise ratio 27 . PtNPs were modified in the plating solution by mixing 48 mM H 2 PtCl 6 and 4.2 mM Pb(CH 3 COO) 2 at a 1:1 ratio.…”