RESUMO
Capybara is considered the largest living rodent and is widespread distributed in the South America and in the Brazilian territory. The purpose of this study was to provide the anatomical description of the brain in the capybara (Hydrochoerus hydrochaeris) using magnetic resonance imaging (MRI). Brains of ten normal capybaras were imaged and sectioned in the anatomical studies. MRI was acquired on 0.25 Tesla equipment, promoting good-quality images capable to identify and classify the main anatomical structures of clinical interest. MRI reference images were validated by comparing them with gross anatomical sections. The capybara sulci and gyri were named for its similar location and orientation to those described in the previous descriptions in the capybara and in the domestic dog. Capybaras presented prominent cerebral sulcus and gyrus in relation to other caviomorph rodents, but in reduced number when compared to domestic animals and other wild mammals such as elephants and giraffes. The findings of this study indicate that the shape of the capybara brain is remarkably similar to that of the caviomorph rodents with a higher neocortilization. The capybara rhinencephalon was well-developed implying a good sense of smell. Due to this development of the rhinencephalon, we can suggest that capybara brain is a macrosmatic brain. The MRI and gross anatomical sections of capybara brain may help veterinary researchers and clinicians increase the accuracy of brain MRI scans interpretation in these animals.
Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Roedores , Animais , Roedores/anatomia & histologia , Imageamento por Ressonância Magnética/veterinária , Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Masculino , FemininoRESUMO
SUMMARY: This study evaluated the morphology of alpacas skin. Biopsies were collected and samples were fixed in 10 % neutral buffered formalin for histological procedures. The sections were stained with hematoxylin and eosin, picrosirius red and Masson's trichrome. Types I, III and IV collagen were analyzed by immunohistochemistry. The derma presented sebaceous and sweat glands, as well as follicular groups with medullated fibers. Type I and type IV collagen were observed at epidermis and dermis as well as in glandular structures and hair follicles. The collagen III, was observed only in dermis.
Este estudio evaluó la morfología de la piel de alpacas. Se recogieron biopsias y las muestras se fijaron en formalina tamponada neutra al 10 % para procedimientos histológicos. Las secciones se tiñeron con hematoxilina y eosina, rojo picrosirius y tricrómico de Masson. El colágeno tipo I, III y IV se analizó mediante inmunohistoquímica. La dermis presentó glándulas sebáceas y sudoríparas, así como grupos foliculares con fibras medulares. Se observó colágeno tipo I y tipo IV en la epidermis y la dermis, así como en estructuras glandulares y folículos pilosos. El colágeno III, se observó únicamente en la dermis.
Assuntos
Animais , Camelídeos Americanos/anatomia & histologia , Tegumento Comum/anatomia & histologia , Imuno-Histoquímica , Microscopia Eletrônica de VarreduraRESUMO
SUMMARY: The celiac, cranial mesenteric and celiacomesenteric ganglia of the paca (Cuniculus paca) were found between the celiac and cranial mesenteric arteries. Two predominant patterns were found: isolated celiac and cranial mesenteric ganglion and the celiacomesenteric ganglion. At the microscopic level, the ganglia are constituted by an agglomeration of neurons surrounded by capsule of connective tissue. Most of these neurons had a single eccentric nucleus. Satellite cells and mast cells were found around the soma. The mast cells were also found ar ound blood vessels and in the capsule of the ganglia.
RESUMEN: Los ganglios celíacos, mesentérico-craneales y celíaco mesentéricos de la paca (Cuniculus paca) se encontraron entre las arterias celíaca y mesentérica craneal. Se visalizaron dos patrones predominantes: celiaca aislada y ganglio mesentérico craneal y ganglio celiaco mesentérico. A nivel microscópico, los ganglios están constituidos por una aglomeración de neuronas rodeadas por una cápsula de tejido conectivo. La mayoría de estas neuronas tenían un solo núcleo excéntrico. Se encontraron células satélites y mastocitos alrededor del soma. Los mastocitos también se encontraron alrededor de los vasos sanguíneos y en la cápsula de los ganglios.
Assuntos
Animais , Masculino , Feminino , Plexo Celíaco/anatomia & histologia , Cuniculidae/anatomia & histologia , Gânglios Simpáticos/anatomia & histologia , Plexo Celíaco/ultraestrutura , Gânglios Simpáticos/ultraestruturaRESUMO
BACKGROUND: The placenta of hystricomorph rodents, lagomorphs and some primates includes an unusual structure, termed a subplacenta, which essentially consists of trophoblastic cells located deep to the central implantation site within the area of decidualization. It has been suggested that the subplacenta is functionally important, although considerable controversy remains on the issue. In this context, our objective was to compare the architecture and structure of the subplacentas of different hystricomorph species, to investigate the possibility that it is active in hormone synthesis. METHODS: In total, the placentas of 3 capybaras (Hydrochaeris hydrochaeris), 2 pacas (Agouti paca), 5 agoutis (Dasyprocta leporina), 5 rock cavies (Kerodon rupestris) and 3 guinea pigs (Cavia porcellus) at different stages of pregnancy (early, middle and near term) were used for gross and microscopic examination. This included the preparation of latex injection casts, immunohistochemistry for steroidogenic enzymes, scanning and transmission electron microscopy. Tissue steroid concentrations were also determined. RESULTS: The gross morphology and microvascular arrangement of the subplacentas were similar among the hystricomorphs studied including ultra-structural verification of cytotrophoblast and syncytiotrophoblast in all species. In guinea pigs, trophoblast cells exhibited characteristics consistent with intense metabolic and secretory activity in general. However, immuno-histochemical evidence also indicated that subplacental trophoblast expressed key steroidogenic enzymes, mainly in the chorionic villus region, consistent with tissue steroid concentrations. CONCLUSIONS: The subplacentas within placentas of hystricomorph rodent species are structurally similar and, in guinea pigs, have potential for steroid hormone secretion from, at least the early stages of pregnancy.
RESUMO
The maned wolf, Chrysocyon brachyurus, is a near-threatened carnivore inhabiting the Brazilian Cerrado. Few studies have been conducted on this species, and even fewer have explored its ophthalmological characteristics. Vision is critical to wild canids; thus, this study aimed to provide a morphoquantitative description of the bulbar conjunctiva of the maned wolf using cytological and histological analyses. Ten healthy maned wolves from a conservational centre, including 4 females and 6 males aged 1-12 years (6.5 ± 2.8), were included in the study. The samples for cytological analysis were collected from the inferior conjunctival sac using a cytobrush, and conjunctival tissue was collected for histological analysis from the temporal canthus zone. The cytological samples were stained using the Papanicolaou method, and the histological sections were stained using haematoxylin and eosin, Periodic acid-Schiff, picrosirius red and Masson's trichrome stains. The cytological samples were studied for stain quality, and the different cell types were counted. Histological examination was used to determine tissue types in the conjunctiva and their proportions. Analyses revealed a stratified squamous epithelium with some goblet cells and eventual pigmentation in the basal layer. Loose connective tissue with the presence of some mononuclear and polymorphonuclear cells was also observed. The epithelium of the maned wolf's bulbar conjunctiva resembles that of dogs and other carnivore species; furthermore, its physiological and pathological responses were similar to those of other carnivore species.