Surface EMG recordings in freely moving rats: a promising method for motor evaluation and for minimizing animal use in research

RIVOLTA, LUCIANO; CANO, LEONARDO ARIEL; TAGASHIRA, CELIA ELINA; MARAÑON, RODRIGO; FARFÁN, FERNANDO DANIEL; ALBARRACÍN, ANA LÍA

Ciudad Autónoma de Buenos Aires

Congreso; XXIV Argentinian Congress of Bioengineering (SABI 2023) and the XIII Clinical Engineering Conference; 2023

Sociedad Argentina de Bioingeniería

Surface electromyography (sEMG) is a widely used technique for recording muscular activity in humans. However, the use of this technique in animal research is mostly limited to equines and have never been described for small mammals. Rodents are widely used in experimental research and are extensively used as models to study the physiology and physiopathology of neurodegenerative diseases. Particularly, motor function evaluations in rodent models of movements disorders is required for evaluating potential therapeutic approaches. In this preliminary work, we are presenting a methodology for obtaining EMG recordings from freely moving rats. The major challenging to obtain accurate signals are related to the electrode design, animal behavior concerns and signal processing. Surface EMG signals were obtained from rat hindlimb biceps femoris muscle. Two animals were used: a parkinsonian rat and a control one. The Parkinson’s disease model was obtained by injecting a neurotoxin into the substantia nigra pars compacta (SNpc) of the left hemisphere. Power spectral densities of the signals were obtained and characterized by the mean and median frequency. We have compared this results with those obtained by using subcutaneous electrodes in a previous work. Power spectral density analysis showed the same tendency for both recording methods. Mean frequency parameters showed significant differences between control and the lesioned rats and for both methodological conditions. These preliminary results are promising for assessing motor function in small animals and freely moving conditions.