Chronic stimulation-induced changes in the rodent thyroarytenoid muscle

Area of Science:

• Laryngeal muscle physiology
• Skeletal muscle adaptation
• Voice disorder research

Background:

• Voice disorder therapies often use skeletal muscle rehabilitation principles.
• The applicability of limb muscle rehabilitation to laryngeal muscles remains untested.
• This study investigates laryngeal muscle adaptability.

Purpose of the Study:

• To examine the feasibility of the rat thyroarytenoid muscle to remodel.
• To assess muscle changes in response to increased activity via chronic electrical stimulation.

Main Methods:

• Twenty Sprague-Dawley rats were used, divided into 1-week and 2-week stimulation groups.
• Nerve cuff electrodes were placed around the recurrent laryngeal nerve for electrical stimulation.
• Thyroarytenoid muscles were isolated for histological and immunohistochemical analysis.

Main Results:

• Muscle fiber area decreased, while neuromuscular junction density and mitochondrial content increased.
• Glycogen-positive fibers increased, indicating endurance-like training adaptations.
• These changes mirror those observed in limb muscles after endurance training.

Conclusions:

• Rat thyroarytenoid muscles demonstrate remodeling capacity in response to chronic electrical stimulation.
• This suggests potential for developing new voice disorder treatments based on muscle rehabilitation.