Lumbosacral plexus in Brazilian Common Opossum

Area of Science:

• Comparative Anatomy
• Neuroscience
• Veterinary Medicine

Background:

• Opossums are valuable biomedical models due to adaptability and reproductive rates.
• Existing literature lacks detailed descriptions of the opossum lumbosacral plexus nerves.
• Understanding peripheral innervation is crucial for utilizing opossums in research.

Purpose of the Study:

• To describe the peripheral innervation of the lumbosacral plexus in the Brazilian Common Opossum (Didelphis aurita).
• To compare the findings with nerve distribution in Eutheria clade species.
• To evaluate the opossum as a model for specific surgical procedures involving the pudendal nerve.

Main Methods:

• Dissection of ten lumbosacral plexuses from Didelphis aurita specimens.
• Detailed description of peripheral nerve distribution in the pelvic limb.
• Comparative analysis with anatomical data from other mammalian species.

Main Results:

• Absence of the tensor fasciae latae muscle and presence of a single sartorius muscle per limb.
• Nerve distribution largely similar to other mammals, with notable exceptions.
• Unique positioning of the pudendal nerve arising from the major ischiatic foramen alongside other sciatic nerves.
• No anatomical variations were observed in the studied specimens.

Conclusions:

• The Brazilian Common Opossum's lumbosacral plexus, particularly the pudendal nerve's position, suggests its utility as a superior model for specific surgical procedures compared to rats or rabbits.
• Pelvic limb nerves are not invariant for muscle homology, challenging previous assumptions.
• Further research on other opossum species is needed to fully understand Methatheria lumbosacral plexus distribution and confirm their suitability for pudendal nerve studies.