OptoZIF Drive: a 3D printed implant and assembly tool package for neural recording and optical stimulation in freely moving mice

Abstract

Objective Behavioral neuroscience studies in freely moving rodents require small, light-weight implants to facilitate neural recording and stimulation. Our goal was to develop an integrated package of 3D printed parts and assembly aids for labs to rapidly fabricate, with minimal training, an implant that combines individually positionable microelectrodes, an optical fiber, zero insertion force (ZIF-clip) headstage connection, and secondary recording electrodes, e.g. for electromyograms (EMG). Approach Starting from previous implant designs that position recording electrodes using a control screw, we developed an implant where the main drive body, protective shell, and non-metal components of the microdrives are 3D printed in parallel. We compared alternative shapes and orientations of circuit boards for electrode connection to the headstage, in terms of their size, weight, and ease of wire insertion. We iteratively refined assembly methods, and integrated additional assembly aids into the 3D printed casing. Main Results We demonstrate the effectiveness of the OptoZIF Drive by performing real time optogenetic feedback in behaving mice. A novel feature of the OptoZIF Drive is its vertical circuit board, which facilities direct ZIF-clip connection. This feature requires angled insertion of an optical fiber that still can exit the drive from the center of a ring of recording electrodes. We designed an innovative 2-part protective shell that can be installed during the implant surgery to facilitate making additional connections to the circuit board. We use this feature to show that facial EMG in mice can be used as a control signal to lock stimulation to the animal's motion, with stable EMG signal over several months. To decrease assembly time, reduce assembly errors, and improve repeatability, we fabricate assembly aids including a drive holder, a drill guide, an implant fixture for microelectode “pinning”, and a gold plating fixture. Significance The expanding capability of optogenetic tools motivates continuing development of small optoelectric devices for stimulation and recording in freely moving mice. The OptoZIF Drive is the first to natively support ZIF-clip connection to recording hardware, which further supports a decrease in implant cross-section. The integrated 3D printed package of drive components and assembly tools facilities implant construction. The easy interfacing and installation of auxiliary electrodes makes the OptoZIF Drive especially attractive for real time feedback stimulation experiments.

The systemDrive: a Multisite, Multiregion Microdrive with Independent Drive Axis Angling for Chronic Multimodal Systems Neuroscience Recordings in Freely Behaving Animals

“…Many microdrives now offer integration of optical fibers for simultaneous electrophysiological recording and optogenetic control of target cell populations (VersaDrive-8 Optical, Neuralynx; Anikeeva et al, 2012; Voigts et al, 2013; Freedman et al, 2016; Liang et al, 2017). However, these designs are limited to single-drive axis targeting, which leaves the potential for large-scale circuit optogenetic interrogations using microdrives untapped.…”

A 3D Printed Device for Low Cost Neural Stimulation in Mice

“…Additive manufacturing, also known as 3D printing, has already been shown to be a powerful and versatile tool for manufacturing neural devices. Notably, some groups have developed microdrive devices with 3D printed bodies suitable for implantation in mice (Voigts et al, 2013; Freedman et al, 2016). Other works have used 3D printing to produce a headstage (Pinnell et al, 2016), waterproof cap (Pinnell et al, 2018), and microdrive housing (Polo-Castillo et al, 2019) to protect electronic implants in rats.…”

A model-based approach for targeted neurophysiology in the behaving non-human primate

“…Rapid prototyping technology has enabled a quiet revolution in neuroscience [11]–[13], [19]–[21]. Combined with medical imaging and computer aided design, much of the guesswork that previously dictated the precision of neurophysiological experimentation has been eliminated.…”