A method to identify, dissect and stain equine neuromuscular junctions for morphological analysis

Area of Science:

• Neuroscience
• Comparative Anatomy
• Muscle Physiology

Background:

• Neuromuscular junction (NMJ) morphology is crucial for understanding synaptic biology and neuromuscular diseases.
• Rodent models are widely used but have limitations for studying nerve length dependency in peripheral neuropathies.
• Large animal models offer potential but present anatomical challenges for NMJ research.

Purpose of the Study:

• To optimize a technique for locating and dissecting NMJs in large mammalian distal limb muscles, specifically in horses.
• To enable reliable morphological analysis of equine NMJs using methods validated in smaller species.
• To enhance cross-species translational research for neuromuscular conditions affecting long motor units.

Main Methods:

• Developed and optimized a technique for NMJ identification and dissection in equine pelvic limb muscles.
• Applied a validated quantification method for NMJ morphology analysis.
• Utilized whole-mounting and visualization techniques for innervation patterns in regional muscle samples.

Main Results:

• Successfully demonstrated reliable dissection, staining, and analysis of equine NMJs.
• Revealed distinct morphological differences in NMJs between equine soleus and other pelvic limb muscles (extensor digitorum longus, tibialis cranialis).
• Confirmed that equine distal pelvic limb muscles can be regionally dissected for NMJ visualization.

Conclusions:

• The optimized technique allows for the localization and analysis of NMJs in large mammal muscle bodies.
• This methodology facilitates the identification of neuroanatomical and neuropathological features in equine models.
• The findings support the use of large animal models for advanced neuromuscular research and disease study.