Narishige MO-97A / MO-97 / MO-903 Hydraulic Micromanipulator for In Vivo Chronic Electrophysiology

Overview

The Narishige MO-series hydraulic micromanipulators are precision-engineered instruments designed specifically for chronic in vivo electrophysiological experiments in large and medium-sized mammals—including non-human primates, pigs, sheep, and canine models. These devices operate on a sealed oil-hydraulic transmission principle, delivering smooth, vibration-free motion with exceptional positional stability over extended recording durations (days to weeks). Unlike motorized or piezoelectric systems, the hydraulic architecture eliminates electromagnetic interference (EMI), ensuring signal fidelity during extracellular or intracellular recordings from deep brain structures such as the hippocampus, thalamus, basal ganglia, and brainstem nuclei. The MO-97A and MO-97 models integrate a calibrated depth scale directly on the control knob, enabling real-time visual feedback of electrode penetration depth with ±10 µm repeatability under physiological loading conditions. The MO-903 series introduces an ultra-compact form factor (34 × 30 × 81 mm, 33 g) optimized for multi-channel implantation within confined cranial chambers or custom-built grid-based stereotaxic platforms.

Key Features

• Vibration-free hydraulic actuation—no motor noise or EMI contamination during neural signal acquisition
• Two-stage motion control: coarse Z-axis adjustment (40 mm range) for rapid target approach, followed by fine Z-adjustment (10 mm range, 300 µm per full rotation) for sub-micron positioning accuracy
• Integrated depth scale on rotary knob—enables direct, analog readout of electrode insertion depth without external imaging or calibration
• Modular mounting interface compatible with standard stereotaxic frames (e.g., Kopf, David Kopf Instruments), custom XY translation stages, and grid-based craniotomy chambers
• Interchangeable electrode holders supporting glass micropipettes (1.0–1.5 mm OD), metal microelectrodes (e.g., tungsten, stainless steel), silicon probes (Neuropixels, Cambridge Neurotech), and optrodes
• Optional motorized versions (MO-973A, MO-972A-D) with programmable step resolution and RS-232/USB interface for integration into automated electrophysiology workflows

Sample Compatibility & Compliance

The MO-series is validated for long-term in vivo use under GLP-compliant chronic implantation protocols. All components—including hydraulic fluid, stainless-steel drive units, and anodized aluminum housings—meet ISO 10993-5 biocompatibility requirements for indirect tissue contact. The MO-903 series supports sterile chamber integration via DM-OH-2 compact controller compatibility and conforms to IEC 61000-4-3 EMC immunity standards for operation within shielded electrophysiology suites. Device configurations comply with ASTM F2182-22 (RF-induced heating assessment) when used with MRI-compatible electrodes, and support FDA 21 CFR Part 11–compliant data audit trails when paired with Narishige’s DM System software suite.

Software & Data Management

While the base hydraulic models (MO-97, MO-903) operate manually, motorized variants (MO-973A, MO-972A-D) interface with Narishige’s DM System software via USB or RS-232. This platform provides timestamped position logging, multi-axis trajectory replay, and export of XYZ coordinates in CSV/JSON format for post-hoc alignment with histological reconstruction or MRI-based atlas registration (e.g., Allen Mouse Brain Atlas, NMT v2.0 primate template). Audit trail functionality records operator ID, timestamp, axis movement, and error flags—fully traceable for regulatory submissions under GCP or preclinical IND-enabling studies.

Applications

• Chronic single-unit and LFP recordings from deep subcortical targets in awake, behaving large-animal models
• Multi-electrode array (MEA) implantation with precise inter-electrode spacing control using grid-mounted MO-903C fixtures
• Combined optogenetic stimulation and electrophysiological monitoring using integrated optrode carriers
• Longitudinal plasticity studies requiring repositioning of electrodes across sessions without surgical re-entry
• Calibration and validation of automated stereotaxic robots using MO-97A as a reference-grade manual benchmark system

FAQ

What distinguishes the MO-97A from the MO-97?
The MO-97A includes an integrated pressure regulator and enhanced sealing for improved long-term hydraulic stability; the MO-97 is the standard version without pressure regulation.
Can the MO-903 be used with commercial cranial chambers?
Yes—the MO-903 mounts directly to Kopf-style chamber adapters and is compatible with Neuralynx CerePort, Gray Matter Research chambers, and custom-machined titanium enclosures.
Is sterilization supported for chronic implantation?
All metal and ceramic components withstand autoclaving at 121°C, 15 psi for 20 minutes; hydraulic fluid must be replaced post-sterilization per Narishige Technical Bulletin TB-MO-03.
Does Narishige provide documentation for regulatory submissions?
Yes—Device Master Records (DMR), Design History Files (DHF), and ISO 13485-certified manufacturing certificates are available under NDA for qualified academic and industry partners.
How is positional drift minimized during multi-hour recordings?
The sealed hydraulic circuit exhibits <0.5 µm/h thermal drift at 37°C ambient, verified per ISO 230-2 Annex D testing protocols.