The Anatomical Origin of the Brachial Plexus in the Greater Cane Rat

Abstract

The brachial plexus is a complex network of nerves that originates from the ventral rami of C5 through T1 nerve roots and provides sensory and motor innervation to the forelimb and pectoral region. There has been an increased use of the Greater Cane Rat (GCR) (Thryonomys swinderianus, Temminck) as an indigenous research rat model in studying the nervous system. There is, however, a dearth of information on the anatomical origin of the brachial plexus of this rodent. In this study, the brachial plexus of the GCR was investigated using six adult greater cane rats, (three males, three females). The brachial plexus primarily originated from the caudal branch of the
ventral rami of cervical nerve 5 (C5), cervical nerve 6 (C6), cervical nerve 7 (C7), cervical nerve 8 (C8), and cranial branch of the ventral ramus of first thoracic nerve (T1). The smaller cranial trunk was formed by the caudal branch of the ventral rami of C5 and C6, while the larger caudal trunk was formed by the ventral rami of C7, C8, and T1. The branch formed by the joining of the ventral rami of C5 and
C6 gave off the phrenic nerve before participating in the formation of the brachial plexus. This study highlighted some of the gross characteristics of the brachial plexus of the GCR, as they provide baseline information on their anatomy. The information generated provides a basis for the GCR’s use as research models for comparative and translational brachial plexus studies, for an increased understanding and management of brachial plexopathies, and to provide a clinical reference point in the assessment of the GCR spinal nerves.