Morphologic and morphometric evaluation of the spinal and peripheral nerves of the brachial plexus in the African palm squirrel (Epixerus ebii)
Purpose: Brachial plexus biology in the African palm squirrel was explored to fill information dearth on the anatomy of the rodent’s nervous system. Principal methodologies: Fourteen adult African palm squirrels (six males and eight females) obtained from the wild were fixed in 10% formalin solution for 48hr and the nerves originating from brachial plexus were carefully dissected. Cotton blocks soaked in 2% hydrogen peroxide were placed on the ventral roots of the plexuses for better visualization of plexus elements and tracing. Key findings: The brachial plexus of the African palm squirrel comprised of the caudal branch of the ventral ramus of the fifth cervical spinal nerve (C5) to the cranial branch of the ventral ramus of the first thoracic spinal nerve (T1). The caudal branch of ventral ramus of C5 and cranial branch of ventral ramus of C6 formed the cranial trunk. The ventral ramus of C6 was bound to the cranial branch of the ventral ramus of C7 to form the middle trunk, while the caudal branch of the ventral ramus of C7 and cranial branch of ventral ramus of T1 constituted the caudal trunk. The peripheral nerve trunks and their respective spinal nerve origin (in parenthesis) were cranial pectoral (C5, C6), suprascapular (C5, C6), subscapular (C5, C6), axillary (C6, C7). Others were musculocutaneous (C6), radial (C6, C7), median (C7, T1) and ulnar (C7, T1). Morphometric analyses indicated that T1 and ulnar nerve were the longest spinal and peripheral nerves, respectively. Also, the musculocutaneous and axillary nerves, were, each, significantly higher in the male than in the female rodent. Conclusion: These results were compared with other rodents to establish species variations.
Keywords: African palm squirrel, brachial plexus, peripheral nerves, thoracic limbs
*Correspondence: ibe.chikera@mouau.edu.ng,+2348032882105
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