CMA Microdialysis Awake Animal Activity System Model 1

Overview

The CMA Microdialysis Awake Animal Activity System Model 1 is a purpose-engineered platform for longitudinal, unanesthetized in vivo sampling and behavioral monitoring of small laboratory animals—primarily rats and mice—during microdialysis experiments. Unlike conventional tethered or restraint-based setups, this system enables free movement while maintaining continuous, stable perfusion and sample collection from intracerebral, cardiac, or peripheral tissue sites. It operates on the principle of dynamic microdialysis: a semi-permeable probe is implanted into target tissue, perfused with physiological solution at controlled flow rates (typically 0.3–2.0 µL/min), and analytes diffuse across the membrane into the dialysate according to concentration gradients. The system’s mechanical architecture—including a low-inertia balance arm, dual-channel swivel joint, and inert tubing pathway—ensures uninterrupted fluidic integrity during spontaneous locomotion, eliminating catheter torsion, kinking, or occlusion over multi-hour to multi-day experimental durations.

Key Features

• Stainless steel and fused quartz dual-channel swivel joint: Provides 360° rotational freedom without tubing entanglement; rated for sustained pressure up to 200 kPa and compatible with standard microdialysis pumps (e.g., CMA 102, BASi MD-1000)
• Low-torque, counterbalanced arm assembly: Minimizes mechanical resistance during animal movement, preserving natural gait and exploratory behavior
• Modular bowl-shaped activity chamber: Configurable with standardized mounting interfaces for integration with video tracking systems (e.g., EthoVision XT, Noldus) and environmental sensors
• Dual-mode collection interface: Supports single-probe automated fraction collection via programmable refrigerated fraction collector (e.g., CMA 142), or manual dual-probe parallel sampling using calibrated microtubes
• Chemically inert fluid path: All wetted components (swivel, tubing, connectors) are certified USP Class VI compliant and resistant to organic solvents, acetonitrile, and acidic/basic mobile phases used in subsequent HPLC-EC or LC-MS analysis

Sample Compatibility & Compliance

The system is validated for use with CMA 71, CMA 72, and CMA 73 microdialysis probes (membrane lengths 2–6 mm; molecular weight cutoffs 6–100 kDa). It supports sampling of neurotransmitters (dopamine, serotonin, glutamate), metabolites (glucose, lactate), peptides, and pharmacokinetic analytes in awake, freely moving subjects. Experimental protocols comply with NIH Guide for the Care and Use of Laboratory Animals and EU Directive 2010/63/EU. Hardware design facilitates ALARA-compliant workflow documentation and is compatible with GLP-aligned study execution when paired with audit-trail-enabled data acquisition software.

Software & Data Management

While the Model 1 hardware operates independently of proprietary software, it integrates seamlessly with industry-standard platforms: CMA Microdialysis Control Software (v5.2+) for pump synchronization and fraction timing; LabChart (ADInstruments) for concurrent physiological signal logging (EEG, ECG, EMG); and third-party analytics suites supporting CSV/ASCII export for statistical modeling (Prism, MATLAB, Python Pandas). All time-stamped fraction files include embedded metadata (animal ID, probe location, flow rate, collection interval), ensuring traceability under FDA 21 CFR Part 11 requirements when deployed with electronic signature-capable LIMS environments.

Applications

• Chronopharmacokinetic profiling of CNS-active compounds in awake rodents
• Real-time monitoring of neurochemical dynamics during behavioral assays (open field, forced swim, fear conditioning)
• Combined microdialysis and localized intracerebral drug infusion (e.g., via dual-lumen probes)
• Cardiovascular metabolite sampling during stress-induced hemodynamic challenges
• Long-duration circadian rhythm studies (>72 h) requiring minimal human intervention

FAQ

Can this system be used with non-human primates or larger rodents?

No—the mechanical design, swivel torque profile, and chamber dimensions are optimized exclusively for mice (18–35 g) and rats (200–500 g). Larger species require custom-engineered load-balanced configurations not covered under Model 1 specifications.

Is sterilization of the swivel joint possible between subjects?

Yes—stainless steel and quartz components tolerate autoclaving (121°C, 15 psi, 20 min) and ethanol/isopropanol immersion; however, repeated thermal cycling may affect quartz-to-metal seal longevity—validation per ISO 17664 is recommended.

Does the system support simultaneous EEG recording?

Yes—dedicated electrode routing ports are integrated into the balance arm housing, enabling co-localized electrophysiology without compromising fluidic stability.

What microdialysis pump models are officially validated?

CMA 102, CMA 470, and BASi MD-1000 microinfusion pumps are factory-tested and documented in the system’s technical validation report (Ref: CMA-TVR-2023-087).