RESUMO
Conditioned responding extinguishes more slowly after partial (inconsistent) reinforcement than after consistent reinforcement. This Partial Reinforcement Extinction Effect (PREE) is usually attributed to learning about nonreinforcement during the partial schedule. An alternative explanation attributes it to any difference in the rate of reinforcement, arguing that animals can detect the change to nonreinforcement more quickly after a denser schedule than a leaner schedule. Experiments 1a and 1b compared extinction of magazine responding to a conditioned stimulus (CS) reinforced with 1 food pellet per trial and a CS reinforced with 2 pellets per trial. Despite the difference in reinforcement rate, there was no reliable difference in extinction. Both experiments did demonstrate the conventional PREE comparing a partial CS (50% reinforced) with a consistent CS. Experiments 2 and 3 tested whether the PREE depends specifically on learning about nonreinforced trials during partial reinforcement. Rats were trained with 2 CS configurations, A and AX. One was partially reinforced, the other consistently reinforced. When AX was partial and A consistent, responding to AX extinguished more slowly than to A. When AX was consistent and A was partial, there was no difference in their extinction. Therefore, pairing X with partial reinforcement allowed rats to show a PREE to AX that did not generalize to A. Pairing A with partial reinforcement meant that rats showed a PREE to A that generalized to AX. Thus, the PREE depends on learning about nonreinforced trials during partial reinforcement and is not because of any difference in per-trial probability of reinforcement. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
Assuntos
Comportamento Animal/fisiologia , Condicionamento Clássico/fisiologia , Ratos Sprague-Dawley/anatomia & histologia , Reforço Psicológico , Animais , Condicionamento Operante/fisiologia , Extinção Psicológica/fisiologia , Feminino , Desempenho Psicomotor/fisiologia , Ratos , Esquema de ReforçoRESUMO
The olfactory bulb (OB) shows special characteristics in its phylogenetic cortical structure and synaptic pattern. In the OB, gamma-aminobutyric acid (GABA), as an inhibitory neurotransmitter, is secreted from GABAergic neurons which contain parvalbumin (a calcium-binding protein). Many studies on the distribution of parvalbumin-immunoreactive neurons in the rodent OB have been published but poorly reported in the avian OB. Therefore, in this study, we compared the structure of the OB and distribution of parvalbumin-immunoreactive neurons in the OB between the rat and pigeon using cresyl violet staining and immunohistochemistry for parvalbumin, respectively. Fundamentally, the pigeon OB showed layers like those of the rat OB; however, some layers were not clear like in the rat OB. Parvalbumin-immunoreactive neurons in the pigeon OB were predominantly distributed in the external plexiform layer like that in the rat OB; however, the neurons did not have long processes like those in the rat. Furthermore, parvalbumin-immunoreactive fibres were abundant in some layers; this finding was not shown in the rat OB. In brief, parvalbumin-immunoreactive neurons were found like those in the rat OB; however, parvalbumin-immunoreactive fibres were significantly abundant in the pigeon OB compared to those in the rat OB.
Assuntos
Columbidae/anatomia & histologia , Bulbo Olfatório/citologia , Parvalbuminas/análise , Ratos Sprague-Dawley/anatomia & histologia , Animais , Benzoxazinas , Corantes , Columbidae/metabolismo , Imuno-Histoquímica/veterinária , Masculino , Bulbo Olfatório/química , Parvalbuminas/imunologia , Ratos , Ratos Sprague-Dawley/metabolismo , Coloração e Rotulagem/veterináriaRESUMO
HAART has brought relief to many living with HIV/AIDS, decreasing morbidity and mortality rates. In spite of these benefits, the treatment has been associated with reproductive disorders. This study is aimed at investigating the effects of Naringenin (Nar) on the expression of testicular 3ß-Hydroxysteroid dehydrogenase (3ß HSD) in HAART-treated Sprague-Dawley rats. 30 adult male Sprague-Dawley rats were randomly divided into six groups. The rats were fed with 30 mg/kg of HAART (Efavirenz+Embtricitabine+Tenofovir), 40mg/kg and 80 mg/kg of Nar and a combination of both HAART and Nar for a period of 70 days. Thereafter, the animals were euthanized and the testes processed. The results showed a significant decrease (p<0.05) in the expression of 3ß HSD in the HAART group compared to controls. However, the co-treatment of HAART with 40 mg/kg Nar increased significantly (p<0.05) the expression of 3ß HSD, compared to HAART and control. The relative volume fraction also showed significant increase (p<0.05) in germinal epithelium, lumen and Leydig cells of animals treated with 80 mg/kg Nar, and HAART+40 mg/kg Nar compared to control and HAART respectively. In conclusion, HAART is causes a deficiency in testicular 3ß HSD, thereby limiting spermatogenesis. However, co-treatment with 40 mg/kg Naringenin increases testicular 3ß HSD expression and enhances spermatogenesis
No disponible
Assuntos
Animais , Ratos , Testículo/anatomia & histologia , Terapia Antirretroviral de Alta Atividade/veterinária , 3-Hidroxiesteroide Desidrogenases/metabolismo , Flavanonas/química , Flavanonas/farmacologia , 3-Hidroxiesteroide Desidrogenases/análise , Ratos Sprague-Dawley/anatomia & histologia , Imuno-Histoquímica , Testículo/efeitos dos fármacos , 3-Hidroxiesteroide Desidrogenases/efeitos dos fármacosRESUMO
BACKGROUND: Microvascular anastomosis is an essential procedure in neurosurgery, but the opportunity to perform the surgery has gradually decreased for neurosurgeons. Therefore, training is necessary for obtaining and maintaining the skills required for the procedure. We describe the detailed anatomy of cervical and femoral regions in rats and discuss the advantages for practicing microvascular anastomosis. METHODS: Cervical regions of Sprague-Dawley rats were dissected under intraperitoneal anesthesia. The step-by-step anatomic description was documented using a high-resolution charge-coupled device image sensor and recording systems. Using this model, temporal occlusion time and patency were measured, and these measures were compared between the trainee and trainer groups. The number of times the training needs to be completed to attain competency in the bypass procedure was estimated. RESULTS: After exposing the carotid triangle, a half-ring was created by end-to-side anastomosis. Anastomosis was performed at the common carotid artery using the contralateral side of the carotid artery as a graft. The cutoff value for the temporal occlusion time was 79.3 minutes in the receiver operating characteristic curve based on a target temporal occlusion time for beginners determined during the training. CONCLUSIONS: Using a living animal model, a trainee has the opportunity to learn not only anastomotic techniques but also hemostatic control as well as overcoming mental strain during surgery. Living animal models are important in training because the fidelity of a living animal model is superior to nonliving models. Applying training using a half-ring model contributes to safe and efficient surgery.
Assuntos
Anastomose Cirúrgica/educação , Procedimentos Neurocirúrgicos/educação , Ratos Sprague-Dawley/anatomia & histologia , Ratos Sprague-Dawley/cirurgia , Animais , Encéfalo/anatomia & histologia , Encéfalo/irrigação sanguínea , Encéfalo/cirurgia , Competência Clínica , Dissecação , Feminino , Internato e Residência , Neurocirurgia/educação , Prática Psicológica , Estudantes de MedicinaRESUMO
Sorafenib is an inhibitor of multi-kinases including tyrosine and serine/threonine kinases. This study investigated the efficacy and safety of sorafenib, an inhibitor of multi-kinases, for the treatment of pulmonary arterial hypertension (PAH), in monocrotaline (MCT)-induced PAH rat models. PAH was induced by subcutaneous (sc) injection of 60 mg/ kg monocrotaline (MCT) dissolved in 0.5 N HCl. Rats were assigned into the following groups: 1) control (C) group, 2) monocrotaline (M) group, and 3) sorafenib (S) group (MCT injection + sorafenib injection group). Rats in the treatment groups received a daily oral gavage of 2.5 mg/kg sorafenib for seven days. Our results showed that sorafenib treatment reduced systolic pulmonary artery pressure (SPAP) in PAH rats, and improved right ventricular (RV) hypertrophy, an indicator of RV pressure overload caused by elevated pulmonary artery pressure. In addition, the number of intraacinar arteries and medial wall thickening in pulmonary arterioles (an index of vascular remodeling) were decreased. Our results revealed that sorafenib reduced ventricular hypertrophy and the expression of fibrosis. These results support the notion that sorafenib improves the functional properties of RV, thereby highlighting its potential benefits for heart and lung impairment
No disponible
Assuntos
Animais , Masculino , Ratos , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/veterinária , Monocrotalina/uso terapêutico , Proteínas Tirosina Quinases/uso terapêutico , Modelos Animais de Doenças , Resultado do Tratamento , Proteínas Tirosina Quinases/antagonistas & inibidores , Ratos Sprague-Dawley/anatomia & histologia , Artéria Pulmonar/anatomia & histologia , Artéria Pulmonar , Tecido Conjuntivo/anatomia & histologia , Tecido Conjuntivo , Western Blotting , Imuno-Histoquímica/métodosRESUMO
Delayed wound healing (the diabetic ulcer) is one of the major complications of diabetes mellitus (DM), which has shown an increasing trend over previous decades to affect almost 15% of diabetic patients. Virgin coconut oil (VCO) is a natural oil rich in vitamins and antioxidants and possesses antimicrobial and antiviral activities. In the current study, we evaluated the effects of topical application of VCO on wound healing in diabetes-induced Sprague-Dawley rats. A total of 72 animals were divided into 4 groups: i.e. (I) non-diabetic nontreated (NN), (II) diabetic non-treated (DN), (III) diabetic treated with VCO (VCO), and (IV) diabetic treated with silver sulfadiazine cream (SS). Wounds were inflicted on all groups using punch biopsy needles, and the animals were treated for 14 days. Wound closure rate (WCR) was measured on day 5, 10, and 14. Histological analysis was performed on day 7 and 14. Total protein content and superoxide dismutase (SOD) activity were measured on day 1, 7, and 14. WCR in VCO group was higher on all days compared to DN. Histological analysis revealed that VCO promoted re-epithelialization and increased collagen content of wound tissue. Total protein content in VCO group was higher on day 7 and 14 compared to both DN and SS groups. VCO showed insignificant effects on SOD levels. In summary, VCO was found to be better than silver sulfadiazine cream in the healing of diabetic wounds via promoting reepithelialization and collagen synthesize as well as increasing WCR and total protein content
No disponible
Assuntos
Animais , Ratos , Óleo de Palmeira/métodos , Cicatrização , Ferimentos e Lesões/terapia , Ferimentos e Lesões/veterinária , Úlcera do Pé/patologia , Pé Diabético/terapia , Glicemia/análise , Ferimentos e Lesões/diagnóstico , Ferimentos e Lesões/patologia , Ratos Sprague-Dawley/anatomia & histologia , Ratos Sprague-Dawley/metabolismo , Sulfadiazina de Prata/uso terapêutico , Superóxido Dismutase/análiseRESUMO
As in many altricial species, rats are born with fused eyelids and markedly underdeveloped eyes. While the normal histology of the eyes of mature rats is known, the histomorphological changes occurring during postnatal eye development in this species remain incompletely characterized. This study was conducted to describe the postnatal development of ocular structures in Sprague-Dawley (SD) rats during the first month of age using histology and immunohistochemistry (IHC). Both eyes were collected from 51 SD rats at 13 time points between postnatal day (PND)1 and PND30. Histologic examination of hematoxylin and eosin-stained sections was performed, as well as IHC for cleaved-caspase-3 and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) to evaluate apoptosis, and IHC for Ki-67 and phospho-histone-H3 to evaluate cell proliferation. Extensive ocular tissue remodeling occurred prior to the eyelid opening around PND14 and reflected the interplay between apoptosis and cell proliferation. Apoptosis was particularly remarkable in the maturing subcapsular anterior epithelium of the lens, the inner nuclear and ganglion cell layers of the developing retina, and the Harderian gland, and was involved in the regression of the hyaloid vasculature. Nuclear degradation in the newly formed secondary lens fibers was noteworthy after birth and was associated with TUNEL-positive nuclear remnants lining the lens organelle-free zone. Cell proliferation was marked in the developing retina, cornea, iris, ciliary body and Harderian gland. The rat eye reached histomorphological maturity at PND21 after a rapid phase of morphological changes characterized by the coexistence of cell death and proliferation.
Assuntos
Olho/crescimento & desenvolvimento , Ratos Sprague-Dawley/crescimento & desenvolvimento , Animais , Animais Recém-Nascidos/anatomia & histologia , Animais Recém-Nascidos/crescimento & desenvolvimento , Apoptose , Proliferação de Células , Corpo Ciliar/anatomia & histologia , Corpo Ciliar/crescimento & desenvolvimento , Córnea/anatomia & histologia , Córnea/crescimento & desenvolvimento , Olho/anatomia & histologia , Feminino , Glândula de Harder/anatomia & histologia , Glândula de Harder/crescimento & desenvolvimento , Histonas/metabolismo , Iris/anatomia & histologia , Iris/crescimento & desenvolvimento , Antígeno Ki-67/metabolismo , Cristalino/anatomia & histologia , Cristalino/crescimento & desenvolvimento , Masculino , Ratos , Ratos Sprague-Dawley/anatomia & histologia , Retina/anatomia & histologia , Retina/crescimento & desenvolvimentoRESUMO
BACKGROUND: Understanding the precise anatomy in experimental animals is crucial for correct design of research projects. Rats are commonly used for scientific research in plastic surgery because of their availability in academic institutions, moderate cost, and sizable vessels for microsurgical procedures. In past publications about rat anatomy, lymphatic mapping has been limited and incomplete. The aim of this study was to comprehensively map the superficial lymphatic system in the rat. METHODS: Twenty-seven Sprague-Dawley rats were used for this study. Indocyanine green fluorescence lymphography was used to identify the lymphatic vessels and lymph nodes. Under general anaesthesia, indocyanine green was injected intradermally at multiple spots along the dorsal and medial midlines, front and hind paws, ears, and tail. The course of the lymphatic vessels was traced on the skin with a marker pen and photographed. The superficial lymphatic vessels in each rat were sketched on a graphic template and all of the templates were superimposed using graphics software to define the relationship between the lymphatic vessel and sentinel node. RESULTS: Indocyanine green fluorescence lymphography was able to demonstrate the superficial lymphatic vessels in the rat. Six groups of regional lymph node/s were identified and lymphatic pathways to those nodes delineated. The authors' lymphosome concept was successfully applied to the rat, with six lymphosomes identified. CONCLUSIONS: The authors succeeded in performing superficial lymphatic mapping in the rat. The authors' anatomical findings can provide further information about the lymphatic system in the normal state and promote understanding of pathologic changes generated by surgical manipulation for future studies.
Assuntos
Linfonodos/anatomia & histologia , Vasos Linfáticos/anatomia & histologia , Modelos Animais , Ratos Sprague-Dawley/anatomia & histologia , Pele/anatomia & histologia , Animais , Feminino , Corantes Fluorescentes , Verde de Indocianina , Linfonodos/diagnóstico por imagem , Vasos Linfáticos/diagnóstico por imagem , Linfografia/métodos , Masculino , Ratos , Pele/diagnóstico por imagemRESUMO
As is well recognized, serotonergic (5-HT) fibers distribute widely throughout the forebrain, including the amygdala. Although a few reports have examined the 5-HT innervation of select nuclei of the amygdala in the rat, no previous report has described overall 5-HT projections to the amygdala in the rat. Using immunostaining for the serotonin transporter, SERT, we describe the complete pattern of distribution of 5-HT fibers to the amygdala (proper) and to the extended amygdala in the rat. Based on its ontogenetic origins, the amygdala was subdivided into two major parts, pallial and subpallial components, with the pallial component further divided into superficial and deep nuclei (Olucha-Bordonau et al. 2015). SERT+ fibers were shown to distributed moderately to densely to the deep and cortical pallial nuclei, but, by contrast, lightly to the subpallial nuclei. Specifically, 1) of the deep pallial nuclei, the lateral, basolateral, and basomedial nuclei contained a very dense concentration of 5-HT fibers; 2) of the cortical pallial nuclei, the anterior cortical and amygdala-cortical transition zone rostrally and the posteromedial and posterolateral nuclei caudally contained a moderate concentration of 5-HT fibers; and 3) of the subpallial nuclei, the anterior nuclei and the rostral part of the medial (Me) nuclei contained a moderate concentration of 5-HT fibers, whereas caudal regions of Me as well as the central nuclei and the intercalated nuclei contained a sparse/light concentration of 5-HT fibers. With regard to the extended amygdala (primarily the bed nucleus of stria terminalis; BST), on the whole, the BST contained moderate numbers of 5-HT fibers, spread fairly uniformly throughout BST. The findings are discussed with respect to a critical serotonergic influence on the amygdala, particularly on the basal complex, and on the extended amygdala in the control of states of fear and anxiety. J. Comp. Neurol. 525:116-139, 2017. © 2016 Wiley Periodicals, Inc.
Assuntos
Tonsila do Cerebelo/citologia , Ratos Sprague-Dawley/anatomia & histologia , Neurônios Serotoninérgicos/citologia , Tonsila do Cerebelo/metabolismo , Animais , Feminino , Imuno-Histoquímica , Masculino , Vias Neurais/citologia , Vias Neurais/metabolismo , Fotomicrografia , Proteínas de Ligação a RNA/metabolismo , Ratos Sprague-Dawley/metabolismo , Receptor 5-HT1A de Serotonina/metabolismo , Neurônios Serotoninérgicos/metabolismoRESUMO
This study refines the characterization of the rat parietal cortical domain in terms of cyto- and chemoarchitecture as well as thalamic connectivity. We recognize three subdivisions of the posterior parietal cortex (PPC), which are architectonically distinct from the neighboring somatosensory and visual cortices. Furthermore, we show that the different parietal areas are differently connected with thalamic nuclei. The medial portion of PPC (mPPC) is connected primarily with the medial portion of the lateral posterior nucleus (LP), whereas the lateral portion (lPPC) connects with the posterior complex (Po). The more caudolateral part of PPC (PtP) also projects to Po but can be distinguished from lPPC based on architectonic criteria. The primary somatic and visual cortices, neighboring PPC, are preferentially connected with the primary ventral posterior and dorsolateral geniculate nuclei, respectively, and less with the associational Po and LP. Particularly the border between the secondary visual cortex and the PPC has been a matter of controversy, but here we show that, although PPC subareas are connected with Po and medial LP, the medial and lateral secondary visual cortices are connected with lateral LP and a portion of medial LP different from that connected with PPC. The resulting delineations and specifications of connectivity with thalamic nuclei together with upcoming studies of cortical connectivity will facilitate detailed studies on the role of the subdivisions of PPC in the rat as diverse, higher order associative cortical areas, comparable to those described in the primate.for J. Comp. Neurol. 524:3774-3809, 2016. © 2016 Wiley Periodicals, Inc.
Assuntos
Lobo Parietal/anatomia & histologia , Ratos Sprague-Dawley/anatomia & histologia , Animais , Feminino , Masculino , Vias Neurais/anatomia & histologia , Técnicas de Rastreamento Neuroanatômico , Marcadores do Trato Nervoso , Tálamo/anatomia & histologiaRESUMO
The main focus of our original article was to describe the anatomical delineations constituting the first version of the WHS Sprague Dawley atlas, apply the Waxholm Space coordinate system, and publish the associated MRI/DTI template and segmentation volume in their original format. To increase usability of the dataset, we have recently shared an updated version of the volumetric image material (v1.01). The aims of this addendum are to inform about the improvements in the updated dataset, in particular related to navigation in the WHS coordinate system, and provide guidance for transforming coordinates acquired in the first version of the atlas.
Assuntos
Atlas como Assunto , Encéfalo/anatomia & histologia , Ratos Sprague-Dawley/anatomia & histologia , Animais , MasculinoRESUMO
Three-dimensional digital brain atlases represent an important new generation of neuroinformatics tools for understanding complex brain anatomy, assigning location to experimental data, and planning of experiments. We have acquired a microscopic resolution isotropic MRI and DTI atlasing template for the Sprague Dawley rat brain with 39 µm isotropic voxels for the MRI volume and 78 µm isotropic voxels for the DTI. Building on this template, we have delineated 76 major anatomical structures in the brain. Delineation criteria are provided for each structure. We have applied a spatial reference system based on internal brain landmarks according to the Waxholm Space standard, previously developed for the mouse brain, and furthermore connected this spatial reference system to the widely used stereotaxic coordinate system by identifying cranial sutures and related stereotaxic landmarks in the template using contrast given by the active staining technique applied to the tissue. With the release of the present atlasing template and anatomical delineations, we provide a new tool for spatial orientation analysis of neuroanatomical location, and planning and guidance of experimental procedures in the rat brain. The use of Waxholm Space and related infrastructures will connect the atlas to interoperable resources and services for multi-level data integration and analysis across reference spaces.
Assuntos
Atlas como Assunto , Encéfalo/anatomia & histologia , Ratos Sprague-Dawley/anatomia & histologia , Animais , Imagem de Difusão por Ressonância Magnética , Substância Cinzenta/anatomia & histologia , Processamento de Imagem Assistida por Computador , Disseminação de Informação , Internet , Masculino , Ratos , Medula Espinal/anatomia & histologia , Substância Branca/anatomia & histologiaRESUMO
BACKGROUND: In many pre-clinical studies of cartilage tissue, it has been generally assumed that the major difference of the tissue between the species is the tissue thickness, which is related to the size of the animal itself. At present, there appear to be lack of studies demonstrating the relationship between chondrocyte densities, protein content, gene expressions and cartilage thickness in the various animal models that are commonly used. The present study was conducted to determine whether or not chondrocyte density, proteoglycan/protein content and selective chondrocyte gene expression are merely related to the cartilage thickness (thus animal size), and not the intrinsic nature of the species being investigated. Mature animals (rabbit, rats and goats) were sacrificed for their hind knee cartilages. Image analyses were performed on five consecutive histological sections, sampled from three pre-defined locations at the lateral and medial femoral condyles. Cartilage thickness, chondrocyte density, Glycosaminoglycan (GAGs)/protein content and gene expression levels for collagen II and SOX-9 were compared across the groups. Correlation analysis was done between cartilage thickness and the other variables. RESULTS: The mean cartilage thickness of rats, rabbits and goats were 166.5 ± 10.9, 356.2 ± 25.0 907.5 ± 114.6 µm, respectively. The mean cartilage cell densities were 3.3 ± 0.4×10(-3) for rats, 2.6 ± 0.3×10(-3) for rabbits and 1.3 ± 0.2×10(-3) cells/µm2 for goats. The mean µg GAG/mg protein content were 23.8 ± 8.6 in rats, 20.5 ± 5.3 in rabbits and 328.7 ± 64.5 in goats; collagen II gene expressions were increased by 0.5 ± 0.1 folds in rats; 0.6 ± 0.1 folds in rabbits, and 0.1 ± 0.1 folds in goats, whilst the fold increase of SOX-9 gene expression was 0.5 ± 0.1 in rats, 0.7 ± 0.1 in rabbits and 0.1 ± 0.0 in goats. Cartilage thickness correlated positively with animals' weight (R2 =0.9856, p = 0.001) and GAG/protein content (R2 =0.6163, p = <0.001). Whereas, it correlates negatively with cell density (R2 = 0.7981, p < 0.001) and cartilage gene expression levels (R2 = 0.6395, p < 0.001). CONCLUSION: There are differences in the composition of the articular cartilage in diverse species, which are not directly dependent on the cartilage thickness of these animals but rather the unique characteristics of that species. Therefore, the species-specific nature of the cartilage tissue should be considered during any data interpretation.
Assuntos
Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Expressão Gênica/fisiologia , Cabras/anatomia & histologia , Proteoglicanas/metabolismo , Coelhos/anatomia & histologia , Ratos Sprague-Dawley/anatomia & histologia , Animais , Cartilagem Articular/citologia , Condrócitos/citologia , Colágeno Tipo II/química , Colágeno Tipo II/genética , Modelos Animais de Doenças , Expressão Gênica/genética , Cabras/genética , Cabras/metabolismo , Histocitoquímica/veterinária , Processamento de Imagem Assistida por Computador , Proteoglicanas/análise , Coelhos/genética , Coelhos/metabolismo , Ratos , Ratos Sprague-Dawley/genética , Ratos Sprague-Dawley/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Análise de Regressão , Fatores de Transcrição SOX9/química , Fatores de Transcrição SOX9/genética , Especificidade da EspécieRESUMO
We examine a previously published branch-based approach for modeling airway diameters that is predicated on the assumption of self-consistency across all levels of the tree. We mathematically formulate this assumption, propose a method to test it and develop a more general model to be used when the assumption is violated. We discuss the effect of measurement error on the estimated models and propose methods that take account of error. The methods are illustrated on data from MRI and CT images of silicone casts of two rats, two normal monkeys, and one ozone-exposed monkey. Our results showed substantial departures from self-consistency in all five subjects. When departures from self-consistency exist, we do not recommend using the self-consistency model, even as an approximation, as we have shown that it may likely lead to an incorrect representation of the diameter geometry. The new variance model can be used instead. Measurement error has an important impact on the estimated morphometry models and needs to be addressed in the analysis.
Assuntos
Brônquios/anatomia & histologia , Macaca mulatta/anatomia & histologia , Modelos Anatômicos , Ratos Sprague-Dawley/anatomia & histologia , Animais , Imageamento por Ressonância Magnética , Masculino , Ratos , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios XRESUMO
Rats are used extensively in abdominal disease research. To monitor disease progress in vivo, high-frequency ultrasound (HFU) can be a powerful tool for obtaining high-resolution images of biological tissues. However, there is a paucity of data regarding the correlation between rat anatomy and corresponding HFU images. Twenty-four adult male Sprague-Dawley (SD) rats underwent abdominal scans using HFU (40 MHz) surgical procedures to identify abdominal organs and major vessels as well as in situ scanning to confirm the imaging results. The results were compared with those of human abdominal organs in ultrasonographic scans. The rat liver, paired kidneys, stomach, intestines, and major blood vessels were identified by HFU and the ultrasonic morphologies of the liver and kidneys showed clear differences between rats and humans. Clinically relevant anatomical structures were identified using HFU imaging of the rat abdomen, and these structures were compared with the corresponding structures in humans. Increased knowledge with regard to identifying the anatomy of rat abdominal organs by ultrasound will allow scientists to conduct more detailed intra-abdominal research in rodents.
Assuntos
Trato Gastrointestinal/anatomia & histologia , Ratos/anatomia & histologia , Animais , Trato Gastrointestinal/diagnóstico por imagem , Trato Gastrointestinal/cirurgia , Masculino , Ratos Sprague-Dawley/anatomia & histologia , Ultrassonografia/métodos , Ultrassonografia/veterináriaRESUMO
Rats are widely used in experimental neurobiological research, and rat brain atlases are important resources for identifying brain regions in the context of experimental microsurgery, tissue sampling, and neuroimaging, as well as comparison of findings across experiments. Currently, most available rat brain atlases are constructed from histological material derived from single specimens, and provide two-dimensional or three-dimensional (3D) outlines of diverse brain regions and fiber tracts. Important limitations of such atlases are that they represent individual specimens, and that finer details of tissue architecture are lacking. Access to more detailed 3D brain atlases representative of a population of animals is needed. Diffusion tensor imaging (DTI) is a unique neuroimaging modality that provides sensitive information about orientation structure in tissues, and is widely applied in basic and clinical neuroscience investigations. To facilitate analysis and assignment of location in rat brain neuroimaging investigations, we have developed a population-averaged three-dimensional DTI atlas of the normal adult Sprague Dawley rat brain. The atlas is constructed from high resolution ex vivo DTI images, which were nonlinearly warped into a population-averaged in vivo brain template. The atlas currently comprises a selection of manually delineated brain regions, the caudate-putamen complex, globus pallidus, entopeduncular nucleus, substantia nigra, external capsule, corpus callosum, internal capsule, cerebral peduncle, fimbria of the hippocampus, fornix, anterior commisure, optic tract, and stria terminalis. The atlas is freely distributed and potentially useful for several purposes, including automated and manual delineation of rat brain structural and functional imaging data.
Assuntos
Atlas como Assunto , Encéfalo/anatomia & histologia , Imagem de Tensor de Difusão/métodos , Ratos Sprague-Dawley/anatomia & histologia , Algoritmos , Animais , Mapeamento Encefálico , Imageamento por Ressonância Magnética , Masculino , Dinâmica não Linear , RatosRESUMO
The goal of the present study was to investigate the effects of ovariectomy and naproxen treatment on both femoral and mandibular bone mass and biomechanical competence. Sprague-Dawley rats were used and divided into five groups: baseline, sham ovariectomized, ovariectomized, sham ovariectomized + naproxen treatment, ovariectomized + naproxen treatment. Mandibles and femurs of the rats were extracted and bone mineral density of the extracted specimens were determined. The volumes and ash weights of the femurs and mandibles were estimated. Maximum loads of the femurs and mandibles were determined by using a three point bending test. Ovariectomy decreased bone mineral density of the femoral midshaft, however naproxen prevented this decrease. Neither ovariectomy nor naproxen treatment affected the BMD in the molar alveolar region. Maximum load was found significantly decreased in the femoral midshaft, however, naproxen treatment prevented this decrease. Maximum load of the molar alveolar region did not significantly change. Naproxen prevents the strength characteristics of femoral midshaft afforded by ovariectomy. However, neither ovariectomy nor naproxen has an effect on the molar alveolar region of the mandible.
El objetivo del presente estudio fue investigar los efectos de la ovariectomía y el tratamiento con naproxeno sobre la masa y la competencia biomecánica del fémur y hueso mandibular. Fueron utilizadas ratas Sprague-Dawley, la que se dividieron en cinco grupos: referencia, ovariectomizadas simuladas, ovariectomizadas, ovariectomizadas simuladas + tratamiento naproxeno, ovariectomizadas + tratamiento naproxeno. Las mandíbulas y los fémures de las ratas fueron extraídos y se determinó la densidad mineral ósea (DMO) de las muestras extraídas. Los volúmenes y pesos de la ceniza fueron estimados. Las cargas máximas de las mandíbulas y fémures se determinaron utilizando un ensayo de flexión de tres puntos. La ovariectomía disminuyó la densidad mineral ósea de la diáfisis media del fémur; sin embargo, el naproxeno impidió esta disminución. Ninguna ovariectomía sin tratamiento de naproxeno afectó a la DMO en la región alveolar molar. La carga máxima se encontró significativamente disminuida en las diáfisis femoral media, pero por el tratamiento de naproxeno no se produjo esta disminución. La carga máxima de la región alveolar molar no cambió en ninguna condición. El naproxeno previene los cambios de resistencia causados por la ovariectomía de la diáfisis media del fémur. Sin embargo, ni la ovariectomía ni el naproxeno tienen un efecto en la región alveolar molar de la mandíbula.
Assuntos
Humanos , Masculino , Recém-Nascido , Dente Molar , Naproxeno/uso terapêutico , Fêmur , Ratos Sprague-Dawley/anatomia & histologia , Ratos Sprague-Dawley/metabolismoRESUMO
El láser infrarrojo emitido por el diodo Arsenurio de Galio (904 nm) proporciona terapia a lesiones articulares por su acción analgésica, cicatrizante y antiinflamatoria, promoviendo a nivel celular síntesis de ATP mitocondrial, modulación de canales de calcio, activando el proceso mitótico e incremento en la síntesis de DNA y de proteínas. Para determinar las dosis que estimulen componentes celulares involucrados en síntesis proteica, del hígado de ratas fueron tomadas muestras de tejido normal e irradiado mediante láser infrarrojo con 1, 2, 4, 8 y 16 Joules/cm2 durante 15 días consecutivos. Fueron tratadas para microscopía electrónica de transmisión y se obtuvieron micrografías con aumentos de 10.000 X. Se realizaron estudios morfométricos, cuantificándose las fracciones volumétricas de núcleos, citoplasma, retículo endoplasmático rugoso (RER), inclusiones de glicógeno, nucleolos, eucromatina y heterocromatina, relación núcleo- citoplasmática y las áreas celulares y nucleares. Los resultados del presente estudio que compara hepatocitos normales e irradiados, indican que existen diferencias significativas en todos los parámetros evaluados. Se concluye que los hepatocitos estimulados alteran su morfología y por ende sus componentes celulares, modificando la función celular determinándose con exactitud la dosis de estimulación infrarroja donde estas células presentan un mayor desarrollo de su maquinaria citoplasmática involucrada en síntesis de proteínas.
The infrared lasser emitted by the Gallium Arsenide diode provides an adequate therapy for articular lessions due to their healing, analgesic, and anti-inflammatory powers. It also promotes at cellular level mitochondrial ATP synthesis, modulates Calcium channels and activate mitotic processes by increasing DNA and protein synthesis. To determine the effective doses which stimulates rat liver protein synthesis, several samples from normal and irradiated tissues to intensities of 1, 2, 4, 8, and 16 Joules/cm2 by 15 consecutive days were taken. These samples were later prepared and observed under transmission E.M. (10000X) and analyzed by morphometric studies, where volume and organelle distribution, such as nucleus, cytoplasm, endoplasmic reticulum, glycogen inclussions, nucleolus, eu and heterochromatin were accounted, together at nuclear-cytoplasmic relationships and the cellular and nuclear areas. Under comparison normal and irradiated hepatocytes presented a significative difference in all evaluated parameters. It can be concluded that at certain specific level of infrared irradiation, hepatocytes alter their morphology by modifyng those cellular components involved in protein síntesis.
Assuntos
Animais , Masculino , Camundongos , Hepatócitos , Hepatócitos/ultraestrutura , Microscopia Confocal/métodos , Microscopia Eletrônica de Transmissão/métodos , Ratos Sprague-Dawley/anatomia & histologia , Terapia a Laser/métodosRESUMO
La terapia con láser de baja potencia ha demostrado tener propiedades analgésicas antiinflamatorias, bioestimulantes y promotoras de la respuesta tisular al daño. El propósito de este estudio fue determinar el efecto que el láser de baja potencia tiene sobre el hueso alveolar dañado. Se utilizaros 13 ratas Sprage Dawley, en las cuales se realizó una lesión estandarizada del hueso alveolar, posterior a lo cual una muestra aleatoria de 7 ratas fue sometida a un protocolo de irradiación de 6 J/cm2, tres veces por semana durante cuatro semanas. Las muestras obtenidas del sitio lesionado en ratas expuestas y no expuestas a la terapia fueron procesadas para hematoxilina eosina, contabilizándose el número de osteonas al microscopio óptico con aumento de 40x. Los resultados muestran un aumento en el número de osteonas en el grupo irradiado, diferencia que resultó estadísticamente significativa (p<0,01), con una alta fuerza de asociación estadística (O.R=5,6 ). Estos resultados sugieren que la terapia láser de baja potencia favorece la respuesta del hueso alveolar dañado.
The Low Level Laser Therapy (LLLT) has demostrated to have analgesic, antiinflamatory, bioestimulant and promoters from the tissues responses properties to the damage. The purpose of this study was determinate the Low Level Laser Therapy effect in the damaged alveolar bone. Thirteen Sprage Dawley rats were used. Total number of animals alveolar bones a standarized lesion was made, later an aleatory sample of seven rats was subjected to the irradiation protocol 6 J/cm², three times per week during four weeks. The obtained samples of the injured area, of exposed and not exposed rats to the laser therapy were processed for hematoxilin & eosin, being the osteon number count by optic microscope with increase of 40x. The result show an increase in the osteon number in the irradiated group, this differentiated was statistically significant (p<0.01), whit a high strength of statistical association (OR=5.6). These result suggest that the therapy laser of low power favors the answer of the damaged alveolar bone.
Assuntos
Adulto , Animais , Feminino , Ratos , Processo Alveolar/anatomia & histologia , Processo Alveolar , Processo Alveolar/fisiologia , Terapia com Luz de Baixa Intensidade/métodos , Terapia com Luz de Baixa Intensidade/veterinária , Osso e Ossos/anatomia & histologia , Osso e Ossos/irrigação sanguínea , Osso e Ossos/lesões , Osso e Ossos/ultraestrutura , Medicina Bucal/métodos , Ratos Sprague-Dawley/anatomia & histologia , Ratos Sprague-Dawley/embriologiaRESUMO
Increasing concern has been expressed about the declining sperm count of humans and the potential environmental effects of both synthetic and natural estrogenic endocrine disruptors (EEDs) on human reproductive health in the last few decades. However, due to paucity of knowledge, we evaluate the chronic reproductive toxicity of sesame phytoestrogenic lignans on the male Sprague Dawley (SD) rats' testis. Thirty adult male SD rats weighing 150-200g were divided into three groups. Two treated groups received a daily dose of aqueous leaves extract of Sesamum radiatum at 14.0 mg/kg bw and 28.0mg /kg bw respectively via gastric gavage, while equal volume of normal saline was administered to the control group for six weeks. Seminal analysis and hormonal assay study were analyzed using SPSS software and P< 0.05 was considered statistically significant. The results showed significant (P< 0.05) body weight gains observed in all the animals with significant (P< 0.05) weight increase in their raw testicular weights compared to control. The relative testicular weight per 100g bw was significantly (P< 0.05) higher in control than treated. However, the weight gain was dose related with a reversal in their relative testicular weight. The cauda sperm count including the motility and morphology of the treated were significantly (P< 0.05) higher than control in a dose related manner. In addition, significant (P > 0.05) increases in testosterone and a significant decrease in FSH in the high dose (treated) compared to control. Sesame phytoestrogenic lignans improves spermatozoa quality in a dose related manner.
Una mayor preocupación se ha expresado en las últimas décadas por la disminución en la cantidad de espermatozoides de los seres humanos y los posibles efectos ambientales de disruptores endocrinos estrogénicos (DES) sintéticos y naturales sobre la salud reproductiva humana. Sin embargo, debido a la escasez de conocimientos, evaluamos la toxicidad crónica para la reproducción de fitoestrógenos lignanos del sésamo en el testículo de ratas Sprague Dawley (SD) macho. Treinta ratas macho adultas, de un peso de 150-200g se dividieron en tres grupos. Dos grupos de tratamiento recibieron una dosis diaria de extracto acuoso de las hojas Sesamum radiatum de 14,0 mg/kg de peso corporal y 28,0mg / kg de peso corporal, respectivamente, a través de una sonda gástrica, mientras que igual volumen de solución salina normal se administró al grupo control durante seis semanas. El análisis seminal y estudio de ensayo hormonal fueron analizados mediante el software SPSS y P <0,05 fue considerado estadísticamente significativo. Los resultados mostraron significativas (P <0,05) ganancias de peso corporal observados en todos los animales con un peso significativo (P <0.05), aumento de peso en su peso testicular bruto en comparación con el control. El relativo peso testicular por 100 g de peso corporal fue significativamente mayor (P <0,05) en control que en tratamiento. Sin embargo, el aumento de peso dosis se ha relacionado con un retroceso en su peso relativo testicular. La cantidad de espermatozoides, incluyendo la motilidad y morfología de los que recibieron tratamiento fue significativamente más alto que el control (P <0,05) en una dosis relacionados. Además, significativo aumento en los niveles de testosterona (P> 0,05) y una disminución significativa de FSH en la dosis alta (tratados), en comparación con el control. Fitoestrógenos lignanos del sésamo mejoran la calidad de los espermatozoides en una dosis adecuada.