No abstract

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.

The red-rumped agouti, a small, wild rodent belonging to the Dasyproctidae family, has great zootechnical potential and adapts well to captivity. In order to contribute to the knowledge regarding the neuroanatomy of the species, the aim of this study was to describe the origin of the nerves forming the lumbosacral plexus by evaluating 12 animals (six males and six females) that had been used in previous experiments. Animals were fixed in a 10% aqueous formaldehyde solution and eviscerated after 72 hours. Major and minor psoas muscles were then retracted to expose the nerves forming the plexus, and the plexus was bleached via cotton soaked in 20-volume hydrogen peroxide for 12 hours for subsequent dissection. Topographical relations of the lumbosacral plexus were grouped into tables and arranged in terms of simple percentages. In seven cases (58.34%), the lumbosacral plexus in the red-rumped agouti stemmed from the ventral roots of the last four lumbar nerves and the first three sacral nerves (Type I: L 4 -S 3 ). In four animals (33.33%), the lumbosacral plexus stemmed from L 5 -S 3 (Type II), and in one case (8.33%) it stemmed from L 5 -S 4 (Type III). Together, our observations demonstrated that the lumbosacral plexus of the red-rumped agouti comprised the lateral femoral cutaneous, genitofemoral, femoral, obturator, sciatic, cranial gluteal, caudal gluteal, and pudendal nerves. Finally, the origin of the lumbosacral plexus and its constituent spinal nerves was similar to what has been described in other rodents, including the rock cavy, lowland paca, and Spix's yellow-toothed cavy. Key words: Anatomy. Dasyprocta leporine. Nerves. Nervous system. Rodent. ResumoA cutia é um roedor silvestre, de pequeno porte pertencente à família Dasyproctidae, com grande potencial zootécnico e que se adapta bem ao cativeiro. De forma a contribuir acerca da biologia da espécie, objetivou-se descrever a origem dos nervos que formam o plexo lombossacral. Foram utilizados 12 animais (6 machos e 6 fêmeas), provenientes de experimentos anteriores. Os animais foram fixados em solução aquosa de formaldeído a 10% e após 72 horas, eviscerados. Em seguida os músculos psoas maior e menor foram rebatidos, expondo-se os nervos que formavam o plexo. Sobre estes nervos foi colocado algodão embebido com peróxido de hidrogênio a 20 volumes, permanecendo por 12 horas seguidas para clareamento e consequente dissecação. As relações topográficas do plexo lombossacral agrupadas em tabelas em forma de porcentagem simples. O plexo lombossacral da cutia originou-se em sete casos (58,34%) a partir das raízes ventrais dos quatro últimos nervos lombares e três primeiros nervos sacrais (Tipo I -L 4 -S 3 ), em quatro animais (33,33%) a partir de L 5 -S 3 (Tipo II) e um caso (8,33%) a partir de L 5 -S 4 (Tipo III). Os nervos que participaram do plexo lombossacral da cutia foram: cutâneo femoral lateral, genitofemoral, femoral, obturatório, isquiático, glúteo cranial, glúteo caudal e nervo pudendo. A origem do plexo lombossacral e os nervos espinhais c...

Detailed knowledge of the arterial system is an important prerequisite when interpreting experimental data in research, as well as in the diagnosis of cardiovascular disease using imaging techniques such as Doppler echocardiography and contrast radiography. Thus, considering the importance of the aortic arrangement, the objective of this study was to describe the collateral arteries of the aortic arch of agoutis in order to establish the standard model, and therefore contribute to studies involving research related to heart disease, and produce information for a more accurate diagnosis in complementary imaging examinations. In this study, 14 adult animals were used, comprising eight males and six females. The vascular system was washed with 0.9% aqueous saline solution and perfused with Neoprene 450 latex coloured with yellow or red pigment, which was subsequently dissected and analysed. One male animal was used for the digital contrast radiography technique perfused with a liquid barium sulphate solution (Bariogel®) (1 g/ml) and Neoprene 450 latex, both diluted 1/3. The aortic arch of the agouti presented with only the brachiocephalic trunk as collateral branch in all the animals studied. Thus, agouti falls into type 1 for mammalian aortic arch vascular arrangements.

ResumoObjetivou-se descrever e sistematizar as artérias da base do encéfalo. Foram utilizados dez gerbils que se encontravam armazenados em freezer no laboratório de Morfofisiologia Animal Aplicada da Universidade Federal Rural do Semiárido. Os animais foram descongelados, incisados na linha mediana para identificação do ventrículo esquerdo, o qual foi perfurado e injetados 3ml de Látex Neoprene 650 na concentração de 20% e no pigmento vermelho. Posteriormente aguardou-se cerca de 1 minuto em virtude da polimerização do Látex e logo após foram fixados por imersão em solução aquosa de Formaldeído a 3,7% e após 72 horas, tiveram os encéfalos removidos da calota craniana para análise de sua superfície ventral. Foi visto que o sistema vertebrobasilar e carótico estiveram presentes em todos os animais analisados, mostrando-se responsável pela vascularização do encéfalo caudal e rostral, respectivamente. As principais artérias observadas no modelo padrão incluem as ímpares: basilar, espinhal ventral, ramo medial da artéria cerebral rostral e as pares: vertebral, cerebelar caudal, cerebelar média, trigeminal, cerebelar rostral, ramo terminal da basilar, carótida interna, cerebral caudal, hipofisária, cerebral média, cerebral rostral, lateral do bulbo olfatório e etmoidal interna. Conclui-se com base nos resultados que a irrigação da superfície ventral encefálica do gerbil foi suprida pelos sistemas vertebro-basilar e carótico de forma equivalente, pertencendo assim ao modelo do tipo II. O circuito arterioso apresentou-se aberto caudalmente e fechado rostralmente, fato que difere do relatado em roedores como capivara, cutia, preá, chinchila e nutria.Palavras-chave: artérias cerebrais, circuito arterioso, roedor, sistema carótico, sistema vertebrobasilar. AbstractThe objective was to describe and systematize the arteries of the base of the brain. Ten gerbils were used, which were stored in a freezer in the Laboratory of Applied Animal Morphophysiology of the Federal Rural Semi-Arid University. The animals were thawed, incised in the midline to identify the left ventricle, which was punctured and injected 3 ml of Latex Neoprene 650 at a concentration of 20% and red pigment. After about one minute the polymerization of the Latex was delayed and afterwards fixed by immersion in 3.7% aqueous Formaldehyde solution and after 72 hours the brain was removed from the skull cap for analysis of its ventral surface. It was observed that the vertebro-basilar and carotid system were present in all animals analyzed, being responsible for the vascularization of the caudal and rostral encephalon, respectively. The main arteries observed in the standard model include the odd: basilar, ventral spinal, medial branch of the rostral cerebral artery and, the pairs: vertebral, cerebellar caudal, cerebellar medial, trigeminal, cerebellar rostral, terminal branch of the basilar, internal carotid, caudal cerebral, Pituitary, middle cerebral, rostral, lateral, olfactory and internal ethmoidal. Based on the results, the irrigation of the ventral bra...

Background: Gerbils (Meriones unguiculatus) are rodents belonging to the Muridae family. Recently, breeding of this species as pets has increased significantly. Animal models are being investigated to study diseases related to the human aortic arch. Despite the importance of the aortic arch in maintaining homeostasis, there is limited data available regarding its morphology in gerbils. This study was performed with the objective of describing the collateral branches of the aortic arch in this animal to establish a standard model and thus contribute to future research on cardiovascular diseases in humans.Materials, Methods & Results: This study used 20 male specimens from previous studies that were frozen and stored at the Laboratory of Veterinary Anatomy of the Federal Rural University of the Semi-Arid Region. After thawing the animals, the thoracic cavity was opened for aortic cannulation. The vascular system was washed using saline solution and Neoprene latex stained with red pigment was injected. Subsequently, the animals were fixed in 10% formaldehyde and were dissected and analyzed 72 h later. The arrangement of the collateral branches of the aortic arch in gerbils was analyzed in all animals. The brachiocephalic trunk, the left common carotid, and the left subclavian artery were observed to originate as collateral branches. The brachiocephalic trunk bifurcated into the right common carotid and the right subclavian arteries. The right and the left subclavian arteries branched into the vertebral artery, the internal thoracic artery, the superficial cervical artery, the costocervical trunk, and the axillary artery.Discussion: Several studies reported in the literature describe the collateral branches of the aortic arch in domestic and wild mammalian species. These studies examined the main arteries that originate directly from the aortic arch and their respective branches, and classified the different anatomical variants of the aortic arch in each species. Three different arrangements have been commonly described. The first type corresponds only to the brachiocephalic artery originating from the aortic arch. The right and the left common carotid arteries and the right and the left subclavian arteries originate from this brachiocephalic artery. This type has already been described in the laboratory rat, catingueiro-deer, cattle, and horses. The second type is characterized by the presence of 2 arteries - the brachiocephalic trunk and the left subclavian artery. The right and the left common carotid arteries and the right subclavian artery originate from the brachiocephalic trunk. This arrangement has been reported in most species already studied such as rodents including the paca, chinchilla, guinea pig, mocó, nutria and the preá. The third type of vascular arrangement is observed in the gerbil. In this species, 3 collateral arteries originate from the aortic arch (the brachiocephalic trunk, the left common carotid, and the left subclavian artery). The right common carotid and the right subclavian artery originate from the brachiocephalic trunk. This vascular model has been described in the manatee, in humans, mice, sauim, and the monkey-nail. Thus, we concluded that the branching pattern of the aortic arch of the gerbil was characterized by the brachiocephalic trunk, the left common carotid, and the left subclavian artery, as has been described in mice, the manatee, monkey-nail, sauim, and humans. Based on these morphological characteristics, gerbils could serve as potential experimental models to study diseases related to the human aortic arch.

The agouti is a wild rodent located almost throughout the Brazilian territory, with great scientific importance and high reproductive potential when farmed. In the clinical routine, clinical and surgical procedures are performed on the nervous system of these animals, such as epidural anesthesia and cerebrospinal fluid (CSF) collection; however, data available are limited in literature on the main points of these procedures in this species. In this aspect, the objective was to describe the vertebromedullary topography of the agouti in order to identify and quantify it, with the intention of expanding the information regarding the clinical-surgical procedures in this system. Ten animals were incised longitudinally in the dorsal median line, removing the skin, the musculature, and dorsal fascia of the vertebral column; then, removed the vertebral arches and consequent exposure of the spinal cord and meninges. The morphometry of the animals was done by obtaining the total length, body length, and crown-rump length, as well as the total length of the spinal cord and its segments. The cervical intumescence in the agouti is located between C4-T1 and measures 2.45 cm. The lumbar intumescence is between L5-L7 and is 2.52 cm long. The cauda equina arises from S2 and the filum terminale from S3. As for the medullary cone, it is located between L7-S1 and is 2.52 cm long. The suggested localization for epidural anesthesia or CSF puncture for laboratory tests in agoutis is the lumbosacral space, with the insertion of the needle to be carried out at angle of 90 in the sphinx position.

ABSTRACT:The cloacal bursa is an organ in fowls, which triggers lymphocyte maturation and transference to other tissues. Since there is scanty information on its morphology in wild species in spite of its importance in the fowls´ immunological system, current analysis describes the arterial vascularization of the cloacal bursa in the greater rhea. Twenty juvenile rheas (male and female), which died of natural causes, were obtained from the Center for the Multiplication of Wild Animals (CEMAS/UFERSA). The animals were dissected and their thoracic aorta cannulated and red-stained Latex Neoprene 650 was introduced. The cloacal bursa was irrigated from the terminal branches of the abdominal aorta similar to the caudal mesenteric artery and to the right and left internal iliac arteries. The right and left internal pudenda arteries originated from the right and left internal iliac arteries which, in their turn, gave rise to cloacalbursa arteries and to the right and left cloacal arteries in all studied animals. The caudal mesenteric artery contributed to the arterial blood of the cloacal bursa in almost all studied animals through the anastomosis of right or left internal pudenda artery, with direct branches to the cloacal bursa. The cloacal bursa of the greater rhea is irrigated by cloacal-bursa arteries and cloacal right and left and also by the mesenteric caudal artery, with small variations with regard to the number and layout of the anastomoses and branches from the arteries. The latter are specific characteristics and differentiate them from standards perceived in other fowls.