Micro-field evoked potentials recorded from the porcine sub-dural cortical surface utilizing a microelectrode array

Abstract

A sub-dural surface microelectrode array designed to detect microfield evoked potentials has been developed. The device is comprised of an array of 350-micron square gold contacts, with bidirectional spacing of 150 microns, contained within a polyimide Kapton material. Cytotoxicity testing suggests that the device is suitable for use with animal and human patients. Implementation of the device in animal studies revealed that reliable evoked potentials could be acquired. Further work will be needed to determine how these microfield potentials, which demonstrate selectivity for one eye, relate to the distribution of the ocular dominance columns of the occipital cortex.

Lead-Free Piezoelectric (Ba,Ca)(Zr,Ti)O3 Thin Films for Biocompatible and Flexible Devices

“…It was reported that Kapton is a polyimide accepted for use in biomedical devices because of its proven biocompatibility . Primary human cortical cells were shown to adhere to Kapton for microelectrode applications . In our experiments, dramatically different responses from each tested cell line were obtained.…”

“…26 Primary human cortical cells were shown to adhere to Kapton for microelectrode applications. 27 In our experiments, dramatically different responses from each tested cell line were obtained. Thus, normal human embryonic kidney cells (HEK 293T) contact inhibition seemed to be abrogated, while cells grew in multilayers covering the entire area of the BCZT-coated Kapton, as opposed to those grown on standard borosilicate cover glass.…”

Transparent arrays of bilayer-nanomesh microelectrodes for simultaneous electrophysiology and two-photon imaging in the brain

“…The pitch between neighbored microelectrode sites is designed to be 400 μm, so that the 32-channel MEA can fit within a 3-mm-diameter circular surgery window. This level of electrode spacing is sufficient to capture the rich spatial information available and have been adopted for many previous studies ( 6 , 28 , 29 ). The scanning electron microscopy (SEM) image shown on the right of Fig.…”

Flexible, foldable, actively multiplexed, high-density electrode array for mapping brain activity in vivo

“…Motor control signals 2 and spoken words 3 can be decoded with substantially improved performance utilizing electrodes spaced 1 mm apart or less. In occipital cortex, arrays with 500 μm spacing have demonstrated micro-field evoked potentials that can distinguish ocular dominance columns 4 . The spatial scale for some pathologic signals is also submillimeter, based on observations of microseizures, microdischarges and high frequency oscillations in epileptic brain 5 , 6 .…”