Multisite electrophysiological recordings by self-assembled loose-patch-like junctions between cultured hippocampal neurons and mushroom-shaped microelectrodes.

Nava Shmoel,Micha E. Spira,Hadas Erez,Silviya M. Ojovan,Eilon Maydan,Noha Rabieh

doi:10.1038/srep27110

Nava Shmoel, Micha E. Spira + Show 4 more

Open Access

https://doi.org/10.1038/srep27110

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Journal: Scientific Reports	Publication Date: Jun 1, 2016
Citations: 63	License type: CC BY 4.0

Affiliation: Hebrew University of Jerusalem

Abstract

Substrate integrated planar microelectrode arrays is the “gold standard” method for millisecond-resolution, long-term, large-scale, cell-noninvasive electrophysiological recordings from mammalian neuronal networks. Nevertheless, these devices suffer from drawbacks that are solved by spike-detecting, spike-sorting and signal-averaging techniques which rely on estimated parameters that require user supervision to correct errors, merge clusters and remove outliers. Here we show that primary rat hippocampal neurons grown on micrometer sized gold mushroom-shaped microelectrodes (gMμE) functionalized simply by poly-ethylene-imine/laminin undergo self-assembly processes to form loose patch-like hybrid structures. More than 90% of the hybrids formed in this way record monophasic positive action potentials (APs). Of these, 34.5% record APs with amplitudes above 300 μV and up to 5,085 μV. This self-assembled neuron-gMμE configuration improves the recording quality as compared to planar MEA. This study characterizes and analyzes the electrophysiological signaling repertoire generated by the neurons-gMμE configuration, and discusses prospects to further improve the technology.

Highlights

That either penetrate the plasma membrane of excitable cells like sharp electrodes[7,13,14,15,16,17,18], or nano-transistor based microelectrode arrays (MEAs) that are mechanically manipulated into the cells[19,20,21,22]
For the first time we report on the significant progress in this gMμEs-MEA technology for multisite in vitro recordings from a mammalian neuronal network
To increase the probability that the neuron’s cell bodies would be in close physical contact with the gMμE-caps we prepared dissociated hippocampal cells from 17 day old rat embryos[33] at a high density of approximately 500,000 cells/ml seeding medium. 200 μl of the cells in the seeding medium were pipetted to the center of the gMμEs-MEAs for 6 h

Summary

Introduction

That either penetrate the plasma membrane of excitable cells like sharp electrodes[7,13,14,15,16,17,18], or nano-transistor based MEAs that are mechanically manipulated into the cells[19,20,21,22]. In recent years our laboratory has developed a new approach in which micrometer-sized, extracellular gold mushroom-shaped microelectrodes (gMμEs) record attenuated synaptic and action potentials exhibiting the characteristic features of intracellular recordings (the IN-CELL recording method). In these studies[23,24,25,26,27,28,29,30] we demonstrated that cultured Aplysia neurons tightly engulf the gMμEs to form a high seal resistance. This manuscript characterizes and analyzes the mechanisms that underlie the generation of the observed electrophysiological signaling repertoire and defines approaches to further improve the neurons-gMμE junction

Methods

Results

Conclusion