Multielectrode arrays with elastomeric microstructured overlays for extracellular recordings from patterned neurons

Abstract

Multielectrode array technology constitutes a promising approach for the characterization of the activity-dependent neuronal plasticity underlying information processing in the nervous system. For this purpose, long-term monitoring and stimulation of cultured neuronal networks with one-to-one neuron-sensor interfacing is advantageous. Existing neurochips that meet these specifications have made use of custom 3D structures requiring clean-room intensive microfabrication techniques. Low-cost fabrication procedures with potential for mass production would facilitate progress in the area. To this end, we have developed a sandwich structure comprising an elastomeric film, microstructured by replica moulding and microhole punching, for neuronal patterning, and a standard planar microelectrode array (MEA), for stimulation and recording. The elastomeric film includes microwells for cell body confinement, and microchannels capable of guiding neurites for network topology specification. The device is formed by overlaying the elastomeric structures on planar arrays. The combination of replica moulding, rapid prototyping and planar MEAs results in low-cost neurochips accessible to most neurophysiology labs. Single neuron patterning and recordings of extracellular potentials are demonstrated.

Multisite Recording of Extracellular Potentials Produced by Microchannel-Confined Neurons In-Vitro

“…With this approach, patterning of mass neuronal cultures has been achieved [19]- [21] and, in conjunction with substrate integrated electrodes, single-site recordings from individual oocytes [22] and myocytes [23] have also been realized. ells and microchannels on a planar multielectrode array [1]. The array was fabricated by photolithographically defining a set of parallel ITO electrodes on a glass substrate.…”

“…We have previously reported on hybrid polymer-MEA devices, fabricated with a combination of soft-lithography and classic photolithography technologies, and demonstrated single-channel extracellular recordings from patterned neurites of isolated neurons [1]. Here we describe multi-point recordings from individual channel-confined neurites in vitro and illustrate the application of this technique to single-cell current source density analysis (scCSD).…”

“…A glass substrate with embedded parallel Indium-Tin-Oxide (ITO) electrodes was sandwiched with a PDMS film containing microwells connected by microchannels. Fabrication procedures have been described previously [1]. Briefly, ITO was sputtered on glass substrates to a resistivity of 80 ohm/sq or purchased with similar resistivity (PGO, Germany).…”

“…The substrates were sonicated in acetone, isopropanol, neutral detergent and milli-Q grade water before assembly with elastomeric overlays. The overlays consisted of PDMS films (60-80 m thick) with microcavities (40 m in diameter) and microchannels (cross section 20 2 5 m fabricated by microhole punching and soft-lithography from SU-8 masters [1] and laid on substrates with only coarse alignment. The sealed-well, as opposite to open-well, configuration was established by spreading silicone grease (Bayer, Germany) over the microwells to electrically insulate them.…”

Feasibility of neuro-morphic computing to emulate error-conflict based decision making.

“…We present evidence that neurons can be effectively guided and directed on these substrates, thus this technique presents a new method for guiding cells using both chemical and topographical cues with an improved capability of longterm guidance given the increased level of confinement. [24] demonstrated the use of silicone elastomer microfluidic channels for guiding neurons towards recording microelectrodes embedded in the substrate. Similar approaches have been developed using structures of agarose gel [25], as well as grooves etched into glass substrates [26] and patterned resist [27].…”