Meeting Abstract

P2-44   -   Comparative neuroanatomy of the felid brachial plexus in Pantherinae (snow leopard, Panthera uncia) and Felinae (Domestic cat, Felis catus) Lindvall, TJ*; Suarez-Venot, AG; Hall, MI; Smith, HF; Midwestern Univeristy; Midwestern University; Midwestern University; Midwestern University, Arizona State University tyler.lindvall@midwestern.edu

The brachial plexus, a network of anterior rami providing the somatic innervation to the forelimb, is of particular importance in felids. Large-bodied pantherines require powerful rotatory and joint stabilizing forelimb muscles to maintain a secure hold on large prey, while smaller-bodied felines are small prey specialists reliant on manual dexterity. Dissections of the brachial plexus of one male and one female snow leopard (Panthera uncia), and two male domestic cats (Felis catus) revealed that the morphology of the brachial plexus was remarkably conserved among the sampled felids. Brachial plexus of both species derives from the ventral rami (VR) of C6-T1. The VR of C6 continues laterally to become n. suprascapularis in P. uncia, while F. catus received contributions from C6 and C7. C7 divides into two divisions, a larger cranial division that communicates with C8, and a smaller caudal division which splits into dorsal and ventral components, both connecting to C8. The caudal dorsal portion of C7 and C8 connect laterally. The caudal ventral portion of C7 forms the classic brachial plexus “M” with fibers from C8 and T1. C8 and T1 emerge together and are connected proximally in P. uncia only. T2 provides a small contribution to the plexus, connected to T1. In addition to the usual set of peripheral nerves, an extra branch of the pectoral nerves supplies m. latissimus dorsi near the axilla, in addition to its usual innervation by n. thoracodorsal. C6 provided minor contributions to n. subscapular and n. musculocutaneous in F. catus but not P. uncia. The most striking difference between species was F. catus radial nerve received contributions from C7, C8, and T1. In sum, functional forelimb differences in prey capture and locomotion between pantherines and felines do not result in differing patterns of forelimb innervation.