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February 2019 TechTip

Improving Research with Smarter Component Designs

Though we’re best known for our no-compromise acquisition systems, Neuralynx also works with leading researchers to develop flexible, robust, and cost-effective animal interface technologies. In this TechTip, we explore some unique features of our latest microdrives, headstages, and optogenetics assemblies. These integrated systems improve the quality of research, reduce risks and delays, and help our partners break new ground by enabling new experiment methods.

Inexpensive, easy, customizable microdrives.

Our research partners need microdrives that are easy to assemble, accurate to adjust, support various electrode insertion patterns, enabled optogenetics, and (of course) are lightweight and low-cost. The new Halo Microdrives were designed to meet these needs.

Designed around lightweight, solid, and durable conical bodies, these microdrives enable researchers access to shuttle drive screws even when wider EIB & headstage configurations are used. The 1mm drive screws are a custom half-moon design with a positive keyed screw head to facilitate confident, incremental depth adjustments of 16 microns for each 1/16th turn with the calibrated Turn Tool. Independent tetrode shuttles provide low backlash adjustments and may also carry references or FLEDs (more on those later). All tetrodes, references, and FLEDs are all funneled through a customizable Exit Tip, dictating the insertion pattern for each experiment. The Exit Tips are perfect for smaller craniotomies, tight groups of tetrodes, or multiple chimneys to target different brain structures.

Name Drive Shuttles Grounds Travel Mass
Halo-28 28 1 11 mm 14 grams
Halo-18 18 1 11 mm 9 grams
Halo-10 10 1 11 mm 6 grams
Halo-10-Mini 10 1 6 mm 3.4 grams
Halo-5 5 1 6 mm 2.0 grams

Well-suited for mouse experiments, Halo-5 and Halo-10-Mini are utilize a light, low-profile custom-fitted EIB to form a rigid, sealed container when assembled, keeping debris out of the microdrive body.

The Halo-10, Halo-18, and Halo-28 are designed for high-density acquisition up to 96 channels with rats or larger subjects. These microdrives are reusable up to 3 times, reducing cost per use, and are compatible with existing standard QuickClip and Omnetics EIBs.

Due to large subject populations and time constraints faced by many of our research partners, ease of assembly was a priority in the Halo’s design. Each Halo Microdrive is matched with assembly jigs, giving the researcher an exploded view during polymicro loading and eliminating errors as the loaded exit tip is attached to the microdrive. We also provide stereotaxic mounts for implantation and all required hardware to make assembly and preparation quicker and easier.

Simple, Reliable Optogenetics?

Our Fiber Mounted LEDs (FLEDs) answer that question, providing a dedicated, simplified, and tiny light source (0.2 grams) inside the microdrive. FLEDs load into the Halo Microdrive like a tetrode shuttle, enjoying the assembly, accessibility, and fine depth adjustment of Halo drive shuttles. The FLEDs are powered through our differential stim channels, avoiding the use of stiff and bulky fiber optic connections to the research subject. FLEDs are available in blue, green, amber, and red and are customizable for fiber length and diameter. For tethered experiments, we designed the FLED Driver to interface software or hardware sequence triggers, output stim onset markers (via TTL) for external systems, and drive current to up to 3 FLEDs. Our Pulse 2.0 software is included for control, and complex sequence generation.

Because light is generated inside the Halo Microdrive, and the current drive is powered through EIB Differential Stimulus lines, FLEDs may be powered directly from a FreeLynx Wireless Acquisition system. This allows totally wireless acquisition and optogenetics stimulus delivery in very small, integrated solution.

Name Wavelength Power
Blue FLED 465 nm 10 mW
Green FLED 525 nm 5 mW
Amber FLED 590 nm 5 mW
Red FLED 625 nm 5 mW

A Better Headstage Connection

Available in 18, 36, or 72 channels, our QuickClip® Headstages are designed to eliminate a number of common connection problems. Chiefly, bent pins, high felt weight due to the leverage of a tall connector, and subject stress or damage due to connection difficulty. QuickClip technology uses high density, high cycle count connectors that magnetically self-align for an easy physical insertion. With a very low profile, both the actual mass and the felt weight of EIB and headstage are reduced. These headstages incorporate advanced video tracking LED patterns, enabling reliable and unambiguous position and direction data. All of our QuickClip headstages and EIBs also incorporate differential stim lines for self reward stimulation, powering FLEDs, joint shock delivery, drug delivery control, eye-blink detection sensors, microphone signals, et cetera.

All of these innovations are thanks to input from our research partners, countless hours of development, and years of experience that we hope will pay off in your lab. If you are interested in becoming a beta tester for some of our latest interface components, or discuss your research needs with us, we would love to hear from you! Please email us at sales@neuralynx.com