Anatomy of the brachial plexus in the Mongolian gerbil (Meriones unguiculatus Milne-Edwards, 1867) Jr H., Oliveira G., Costa H., Lopes P., Oliveira R., Bezerra F., Moura C., Oliveira M. (2018): Anatomy of the brachial plexus in the Mongolian gerbil (Meriones unguiculatus Milne-Edwards, 1867). Veterinarni Medicina, 63: 476-481.
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The Mongolian squirrel is a murine rodent widely used as an experimental model and kept as a pet. With respect to the significance of the brachial plexus, we aimed to describe the origin and the nerves that constitute it, providing new information about the neuroanatomy of this species. Twenty adult animals were used, which were fixed in a 10% formaldehyde solution at the Applied Animal Morphophysiology Laboratory of the Brazilian Federal University of the Semi-Arid Region (UFERSA). The animals were medially incised with an opening of the thoracic cavity, and then bilateral dissection was carried out. Once the nerves were identified, cotton wool soaked with a 2% hydrogen peroxide solution was added for bleaching and better visualisation of structures. The gerbil brachial plexus derived from ventral roots of the fourth, fifth, sixth, seventh and eighth cervical nerves (C4–C8) and the first thoracic root (T1). The suprascapular nerve was formed from the nerve roots C4 and C5; the subscapular and cranial pectoral nerves from C5 and C6; the musculocutaneous and axillary nerves from C5, C6 and C7; and the caudal pectoral, radial, median, ulnar, thoracodorsal, lateral thoracic and long thoracic nerves from C7, C8 and T1. This resembles what is described in other rodents, such as the rat and capybara. The gerbil has a pre-fixed plexus conformation.

A˚gren G., Zhou Q., Zhong W. (1989): Ecology and social behaviour of Mongolian gerbils,Meriones unguiculatus, at Xilinhot, Inner Mongolia, China. Animal Behaviour, 37, 11-27
Akao Nobuaki, Tomoda Misato, Hayashi Eiji, Suzuki Ryoko, Shimizu-Suganuma Masumi, Shichinohe Kazuhiro, Fujita Koichiro (2003): Cerebellar ataxia due to Toxocara infection in Mongolian gerbils, Meriones unguiculatus. Veterinary Parasitology, 113, 229-237
Araujo Jr HN, Oliveira GB, Silva AVN, Oliveira REM, Camara FV, Oliveira Jr CM, Bezerra FVF, Oliveira MF (2016): Origin and distribution of the brachial plexus in the Spix’s yellow-toothed cavy (Galea spixii Wagler, 1831) (Rodentia, Caviidae). Veterinární Medicína, 61, 337-343
Ayidin A. (2012): Brachial plexus of the porcupine (Hystrix cristata). Veterinární Medicína, 48, 301-304
Aydin A. (2011): The spinal nerves that constitute the brachial plexus in the red squirrel (Sciurus vulgaris). Veterinární Medicína, 56, 405-408
Batsaikhan N, Tsytsulina K (2016): Meriones unguiculatus. The IUCN Red List of Threatened Species: 2016-3. Available at
Berry M, Bannister LH, Standring SM (1995): Nervous system. In: Williams PL (ed.): Gray’s Anatomy. 38th edn. Churchill Livingstone. 1266–1275.
Brunelli G, Brunelli F (1989): Brachial plexus injuries. In: Lamb DW, Hooper G, Kuczynski K (eds): The Practice of Hand Surgery. 2nd edn. Blackwell Scientific Publications. 218–227.
Canta Annalisa, Meregalli Cristina, Chiorazzi Alessia, Carozzi Valentina A., Crippa Luca, Marmiroli Paola, Cavaletti Guido (2010): The ventral caudal nerve: a physiologic-morphometric study in three different rat strains. Journal of the Peripheral Nervous System, 15, 140-146
Casals JB, Pieri NCG, Feitosa MLT, Ercolin ACM, Roballo KCS, Barreto RSN, Bressan FF, Martins DS, Miglino MA, Ambrosio CE (2011): The use of animal models for stroke research: a review. Comparative Medicine 61, 305–313.
Cooper G, Schiller A (eds) (1975): Anatomy of the Guinea Pig. Harvard University Press. 392 pp.
Costa Herson da Silva, Oliveira Gleidson Benevides, Oliveira Radan Elvis Matias, Araújo Hélio Noberto, Souza Zuliete Aliona Araújo, Moura Carlos Eduardo Bezerra, Oliveira Moacir Fraco (2017): Vascularização arterial da base do encéfalo do gerbil (Meriones unguiculatus Milne-Edwards, 1867). Revista Brasileira de Ciência Veterinária, 24, 12-17
Costabeber Ijoni, de Almeida Gustavo Moura, Becker Mônica, da Silveira Aron Ferreira, Martini Dorival Terra (2010): Brachial Plexus Cords: a Morphological Study. Brazilian Journal of Anesthesiology, 60, 614-619
Dyce KM, Sack WO, Wensing CJG (2010): Textbook of Veterinary Anatomy (in Portuguese). 4th edn. Elsevier. 856 pp.
Fioretto E. T., Souza Castro M. F., Guidi W. L., Mainardi R., Souza R. R., Ribeiro A. A. C. M. (2003): Gross Anatomic Organization of the Capybara's (Hydrochaeris hydrochaeris) Brachial Plexus. Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C, 32, 169-174
Gamba Conrado De Oliveira, Castro Tiane Ferreira de, Rickes Eduardo Madruga, Pereira Malcon Andrei Martinez (2007): Sistematização dos territórios nervosos do plexo braquial em chinchila (Chinchilla lanigera). Brazilian Journal of Veterinary Research and Animal Science, 44, 283-
Gardner ED, Gray DJ, O’Rahilly R (1975): Anatomy: regional study of the human body (in Portuguese). 4th edn. Guanabara Koogan. 891 pp.
Ginsberg M D, Busto R (1989): Rodent models of cerebral ischemia.. Stroke, 20, 1627-1642
Greene EC (ed.) (1963): Anatomy of the rat. In: Transaction of the American Philosophical Society. New Series 27, Hafner Publishing Company. 370 pp.
Guimaraes RT, Birck AJ, Filadelpho AL, Guimaraes GC, Barcelos RP (2013): Origin and distribution brachial plexus nutria (Myocastor coypus) (in Portuguese). Revista Cientifica Eletronica de Medicina Veterinaria 20. Available at
Hill WCO (1972): Primates: Comparative anatomy and taxonomy. Cebidae: Part B. Edinburgh University Press. 537 pp.
ICVGAN – International Committee on Veterinary Gross Anatomical Nomenclature (2017): Nomina Anatomica Veterinaria. 6th edn. World Association on Veterinary Anatomists. 178 pp.
Kaplan Harriett, Miezejeski Charles (1972): Development of seizures in the Mongolian gerbil (Meriones unguiculatus).. Journal of Comparative and Physiological Psychology, 81, 267-273
Kerr AT (1918): The brachial plexus of nerves in man: The variations in its formation and branches. Developmental Dynamics 23, 285–395.
Kirino Takaaki (1982): Delayed neuronal death in the gerbil hippocampus following ischemia. Brain Research, 239, 57-69
Kirino T., Sano K. (1984): Fine structural nature of delayed neuronal death following ischemia in the gerbil hippocampus. Acta Neuropathologica, 62, 209-218
KOIZUMI MASAHIRO, SAKAI TATSUO (1997): On the morphology of the brachial plexus of the platypus (Ornithorhynchus anatinus) and the echidna (Tachyglossus aculeatus). Journal of Anatomy, 190, 447-455
Loskota W.J, Lomax P (1975): The Mongolian gerbil (Meriones unguiculatus) as a model for the study of the epilepsies: EEG records of seizures. Electroencephalography and Clinical Neurophysiology, 38, 597-604
Loskota W. J., Lomax P., Rich S. T. (1974): The Gerbil as a Model for the Study of the Epilepsies.. Epilepsia, 15, 109-119
Miller RA (1934): Comparative studies upon the morphology and distribution of the brachial plexus. Developmental Dynamics 54, 143–175.
Parada HH, Pineda UH, Lagunas EM, Vidal HH (1989): Anatomical variations of the spinal branches that constitute the trunks of origin of the brachial plexus (rami ventralis): (plexus brachialis) in term human fetuses (in Spanish). Anales de Anatomia Normal 7, 32–36.
Reede DL, Holliday RA (eds) (2003): Brachial plexus. In: Head and Neck Imaging. 4th edn. Mosby. 2216–2218.
Resnick D (ed.) (1995): Diagnosis of Bone and Joint Disorders. 3rd edn. WB Saunders Company. 3500–3511.
Scavone ARF, Machado MRF, Guimaraes GC, Oliveira FS, Gerbasi SHB (2008): Origin and distribution analyses of the brachial plexus peripheral nerves of paca (Agouti paca Linnaeus, 1766) (in Portuguese). Ciencia Animal Brasileira 9, 1046–1055.
Schwentker V (1963): The gerbil, a new laboratory animal. Illinois Veterinarian 6, 5–9.
Smith Darci R., Steele Keith E., Shamblin Joshua, Honko Anna, Johnson Joshua, Reed Christopher, Kennedy Maureen, Chapman Jennifer L., Hensley Lisa E. (2010): The pathogenesis of Rift Valley fever virus in the mouse model. Virology, 407, 256-267
Somova L.I., Gregory M.A., Nxumalo E.N. (2000): Mongolian gerbil (Meriones Unguiculatus) as a model of cerebral infarction for testing new therapeutic agents. Methods and Findings in Experimental and Clinical Pharmacology, 22, 203-
Sugiyama T (1965): On the plexus brachialis of Macacus cyclopsis. Acta Medica Nagasakiensia 9, 65–68.
Thompson J. (1970): Parallel spindle systems in the small muscles of the rat tail. The Journal of Physiology, 211, 781-799
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