ONIX is a high-performance acquisition system that minimizes animal burden, provides extremely high performance real-time capabilities, and is compatible with a variety of different recording technologies, e.g. Neuropixels/silicon probes, and Miniscopes.

Key Features

• Acquire from Neuropixels probes, silicon probes, tetrodes, Miniscopes, and more

• Hardware synchronization of all data sources

• Sub-millisecond, software-in-the-loop, closed-loop latencies (~300 µsec with 2x Neuropixels 2.0 probes in Bonsai)

• Absolute head orientation acquisition and torque-free commutator compatibility on select headstages

• Real-time 3D tracking using virtual reality base stations on select headstages

• Integrated optical and electrical stimulation on select headstages

• Runs in Windows with Bonsai and the Open Ephys GUI

Connectivity

• Two high-throughput ONI headstage ports for simultaneous, multimodal acquisition (150 MB/s per port, equivalent to 5000 channels of spike-band electrophysiology data, at 30 kHz)

• Micro-coax tether is 0.31 mm in diameter and ultraflexible

• PCIe-based communication from the ONIX controller to the PC with a breakout board for I/O

• 8 digital inputs, 8 digital outputs (1 MHz/ch)

• 12 analog inputs or outputs (100 kHz/ch, 16-bits/sample)

• Direct compatibility with the Harp family of devices

ONIX offers lighter and more flexible tethers

Because the ONI specification allows communication over a single wire, ONIX uses a single coaxial cable, making ONIX tethers lighter and thinner than those of other systems. The ONIX micro-coax tether measures only 0.31 mm in diameter, compared to the 12-wire digital tether used in SPI-based systems whose thinnest variant is 1.8 mm. It is thinner and far more flexible than the twisted pair used by IMEC Neuropixels systems, and tethers do not need to be a fixed length. ONIX tethers can extend up to 10 m, since the system auto-adjusts the voltage supply to maintain performance.

Promotes natural behavior in large arenas

The ONIX system was designed to minimize interference with natural animal behavior. The flexible and lightweight single tether works in combination with our torque-free commutator that actively rotates in response to the real-time head orientation data. This preempts tether twisting and head torque. Together, these features enable long-term, unrestricted naturalistic locomotion behavior comparable to that of the unimplanted animal, allowing the subject to explore, run, and jump normally.

With the ONIX micro-tether, animals explore and jump freely in a large arena, just as they would without an implant, while thicker tethers impair their natural movement. For more details, see [1].

3D capable headstages for ONIX

ONIX headstages with an onboard 9-axis inertial measurement unit (IMU) can get high-resolution absolute orientation measurements (yaw, pitch, and roll) at the same time as neuronal recordings. Head orientation data can be used to characterize animal behavior, as well as to drive our torque-free commutators. 

Torque- and tangle-free commutation for long recording sessions

Commutators provide a tangle-free connection between the ONIX breakout board and the headstage on a freely moving animal. Our commutators rely on sensing the real-time absolute orientation of the headstage to rotate the tether. This allows experiments to run for extended durations, including multiple days (and even months!), without interruptions due to tether twisting or animal fatigue.

A dual-coaxial commutator is available to get data from two headstages at the same time, allowing researchers to combine, for example, two neuropixels headstages (1536 ch from four probes) or a miniscope and two neuropixels probes.

Use ONIX with Bonsai and the Open Ephys GUI

Running ONIX within Bonsai with the OpenEphys.Onix1 package enables acquisition of multiple ONIX data streams simultaneously with supported cameras and behavioral hardware. It is possible to achieve sub-ms closed-loop latencies including real-time processing in Bonsai. We provide example workflows to help you get started.

The system also runs in the Open Ephys GUI via the ONIX Source plugin, providing users with a familiar modular framework and graphical interface with specialized ephys visualizers like the Probe Viewer for dense Neuropixels probes. You can get the best of both worlds using the Ephys Socket Plugin which streams data directly from Bonsai to the Open Ephys GUI.

3D tracking on compatible headstages

Some ONIX headstages, such as Headstage Ephys 64ch, can acquire 3D positional information simultaneously with neural and other data streams in the same device. Light sensors on the headstage capture infrared laser sweeps from virtual reality base stations placed overhead the arena, tracking the animal’s location in 3D space with millimeter-level precision within a ~10 m3 area. Because the sensors are headborne, this approach avoids heavy data post-processing and multiple views required for video-based 3D positional tracking and multiple animals can be tracked simultaneously using the same base stations.

Optogenetic and electrical stimulation with sub-millisecond closed-loop latency

ONIX can drive both onboard headstage stimulators and external devices via digital outputs with near-instantaneous response times for closed-loop experiments.

The ONIX Headstage Ephys 64ch includes 2 optical stimulators and 1 electrical stimulator, programmable with arbitrary patterns. These stimulators can be triggered based on real-time software processing of the data being acquired in order to, for example, react to individual spikes. The system can achieve sub-millisecond latency from neural voltage acquisition to host PC processing and back to the headstage.