The lumbosacral plexus in two Didelphis species (Didelphidae, Didelphimorphia): origin and nerve distribution.

Morphological studies provide knowledge that allow us to understand how animals interact with the natural environment or the captivity. The goal of this study was to describe the origin and antimeric distribution of lumbosacral plexus nerves in Didelphis aurita and D. albiventris. Fourteen adult cadavers of D. aurita, seven males and seven females, and 13 adult cadavers of D. albiventris, nine males and four females were used. The specimens were sexed, identified, fixed and dissected until the origins of the lumbosacral plexus nerves were exposed. Data were represented as absolute frequency and simple percentage. The lumbosacral plexuses derived a trunk for the femoral and obturator nerves from the ventral branches of L3-L4 (75%) in D. aurita, and in D. albiventris the femoral nerve of L3-L4 (73.1%) and the obturator nerve of L3-L4 (61.5%). In both species, formation of a lumbosacral trunk derived from L5-L6-S1 occurred in 78.6% of D. aurita and 61.5% of D. albiventris. The origin and distribution of lumbosacral plexus nerves of the studied species present similarities with domestic and wild eutherian mammals.