A new electrode configuration for recording electromyographic activity in behaving mice

Area of Science:

• Neuroscience
• Biomedical Engineering
• Animal Physiology

Background:

• Accurate electromyographic (EMG) recordings are crucial for understanding motor physiology in mice.
• Existing methods for EMG recording in behaving mice can be invasive and may affect natural movement.

Purpose of the Study:

• To develop and validate a simple, reliable method for fabricating and implanting fine EMG electrodes in multiple muscles of adult mice.
• To assess the utility of this technique for recording muscle activity during various behaviors and in genetically modified animal models.

Main Methods:

• A novel surgical technique for implanting fine EMG electrodes, minimizing muscle damage and lead interference.
• Simultaneous recording of EMG activity during walking, swimming, and scratching in normal adult mice.
• Kinematic analysis using reflective markers and a commercial motion analysis system to synchronize with EMG data.

Main Results:

• Excellent EMG recordings were achieved from vastus lateralis, tibialis anterior, and gastrocnemius muscles during locomotion, swimming, and scratching.
• The electrode implantation method demonstrated minimal influence on leg movements, even in distal muscles.
• Successful EMG recordings were obtained in a mutant EphA4 mouse, showcasing the method's applicability to genetically modified animals.

Conclusions:

• The described method provides a simple and reliable approach for high-quality EMG recordings in behaving mice.
• This technique is suitable for studying motor control in both normal and genetically modified mouse models.
• The integration with kinematic analysis allows for comprehensive investigation of motor patterns and muscle function.