Two-dimensional jaw tracking and EMG recording system implanted in the freely moving rabbit

Area of Science:

• Biomedical Engineering
• Neuroscience
• Animal Models

Background:

• Accurate measurement of jaw movement and muscle activity is crucial for understanding mastication.
• Existing methods may be invasive or limit animal mobility.
• A need exists for a reliable, long-term system for simultaneous recording.

Purpose of the Study:

• To design and test a novel system for simultaneous recording of mandibular position and masticatory muscle activity.
• To evaluate the system's performance in freely moving rabbits.
• To assess the feasibility of long-term data acquisition.

Main Methods:

• Implantation of magnetic sensors in rabbit maxillary bone and a rare earth magnet on incisors.
• Recording of masseter electromyography (EMG) using fine wire electrodes and a custom amplifier.
• Signal processing and data recording on instrumentation tape for freely moving rabbits over 24 hours.

Main Results:

• The system successfully recorded mandibular position in the sagittal plane and masseter EMG simultaneously.
• The device operated without issues for over 24 hours in freely moving rabbits.
• Implanted magnetic sensors demonstrated stability for over 4 months, enabling long-term studies.

Conclusions:

• A robust and simple system for simultaneous, long-term recording of mandibular dynamics and muscle activity in rabbits was developed.
• This technology facilitates in-vivo research on masticatory function and related neurological processes.
• The system's stability and ease of reimplantation support its utility for extended animal studies.