12 research outputs found
Influencia del estrechamiento del canal vertebral y del tiempo para la descompresión en la recuperación locomotora de ratas
OBJETIVO: o objetivo deste trabalho foi estudar as consequências da lesão por contusão da medula espinhal, associada ao estreitamento do canal vertebral, no comportamento motor de ratos, avaliando-se o efeito do tempo para descompressão na recuperação neurológica dos animais. MÉTODOS: foram utilizados ratos Wistar machos (n=6 por grupo), subdivididos nos seguintes grupos experimentais: laminectomia (T9-T10, Grupo Controle), contusão por queda de peso (10 g de peso, 15 cm de altura), estreitamento do canal vertebral em 35% (hastes de policarbonato; espessura de 0,78 mm) e contusão associada ao estreitamento do canal vertebral. O grupo de lesão associada foi ainda subdividido em sem ou com descompressão 24 ou 72 horas após a cirurgia. Os animais foram sacrificados sete dias após os procedimentos cirúrgicos. A função locomotora dos animais foi avaliada por meio do teste do campo aberto, do teste do plano inclinado e pela aplicação da escala BBB, antes da cirurgia, 24 e 72 horas depois da cirurgia e após 7 dias do procedimento cirúrgico. RESULTADOS: a lesão por queda de peso e compressão da medula espinhal, bem como a lesão mista, prejudicaram o comportamento motor dos animais, sendo que a descompressão cirúrgica após 24 e 72 horas da cirurgia não melhorou a recuperação motora dos animais, como mostram os resultados da avaliação de campo aberto, no plano inclinado e pela escala BBB. Por outro lado, os animais que sofreram lesão medular por queda de peso apresentaram melhores escores na escala BBB e ângulos maiores no plano inclinado do que aqueles que sofreram lesão por estreitamento do canal vertebral ou lesão mista. CONCLUSÕES: a lesão por queda de peso ou estreitamento do canal vertebral provocou alterações no comportamento motor dos animais, sendo que a descompressão não trouxe melhora funcional significativa.OBJECTIVE: the aim of this study was to investigate the consequences of contusion injury of spinal cord associated with narrowing of vertebral canal on motor behavior of rats, as assessing the effect of decompression time on the neurologic recovery of the animals. METHODS: male Wistar rats (n=6 per group) were divided into three experimental groups: submitted to laminectomy (T9-T10, Control Group), contusion due to weight drop (10 g from a height of 15 cm), 35% narrowing of the vertebral canal obtained with 0.78 mm thick polycarbonate rods and contusion injury associated with narrowing of the vertebral canal. In this last group, decompression was not performed or it was made after 24 or 72 hours of the surgery, as the animals were divided into subgroups. Rats were sacrificed seven days after surgical procedures. The motor behavior of the animals was assessed in open arena, inclined plane and by means of Basso, Beattie, and Bresnahan (BBB) locomotor rating scale, before and after 24, 48 hours and 7 days of surgical procedures. RESULTS: contusion injury, narrowing of the spinal canal and mixed injury impaired the motor behavior of the animals. Surgical decompression (24 and 72 hours) did not improve motor recovery as assessed in open arena, BBB scale and inclined plane test. On the other hand, animals injured with weight drop showed better scores on BBB scale and higher angles in the inclined plane when compared to the ones that were injured with narrowing of the vertebral canal and mixed lesion. CONCLUSIONS: spinal cord injury by weight drop and narrowing of the vertebral canal induced alterations on the motor behavior, which did not significantly improve with decompression.OBJETIVO: estudiar las consecuencias de la lesión por contusión de la médula espinal, asociada al estrechamiento del canal vertebral en el comportamiento de ratas, evaluando el efecto del tiempo para la descompresión en la recuperación neurológica de los animales. MÉTODOS: fueron utilizadas ratas Wistar machos (n=6, por grupo), subdivididos en los siguientes grupos experimentales: laminectomÃa (T9-T10, Grupo Control), contusión por caÃda de peso (10 g de peso, 15 cm de altura), estrechamiento del canal vertebral de 35% (astas de policarbonato; espesura de 0.78 mm) y contusión asociada al estrechamiento del canal vertebral. El grupo de lesión asociada fue subdividido en sin o con descompresión, 24 o 72 horas después de la cirugÃa. Los animales fueron sacrificados siete dÃas después de los procedimientos quirúrgicos. La función locomotora de los animales fue evaluada por medio del teste de campo abierto, del plano inclinado y por la aplicación de la escala BBB, antes de la cirugÃa, 24, 72 horas y 7 dÃas después del procedimiento quirúrgico. RESULTADOS: la lesión por caÃda de peso y compresión de la médula espinal, asà como la lesión mixta perjudicaron el comportamiento motor de los animales, siendo que la descompresión quirúrgica 24 y 72 horas después de la cirugÃa no mejoró la recuperación motora de los animales, cuando los mismos fueron evaluados en el campo abierto, en el plano inclinado y por la escala BBB. Por otro lado, los animales que sufrieron lesión medular por caÃda de peso presentaron mejores Ãndices en la escala BBB y ángulos mayores en el plano inclinado, cuando comparados con aquellos que sufrieron lesión por estrechamiento del canal vertebral o la lesión mixta. CONCLUSIONES: la lesión por caÃda de peso o estrechamiento del canal vertebral provocó alteraciones en el comportamiento motor de los animales, siendo que la descompresión no trajo mejorÃa funcional significativa
Dopamina, óxido nÃtrico e suas interações em modelos para o estudo da esquizofrenia Dopamine, nitric oxide and their interactions in models for the study of schizophrenia
Modelos experimentais baseados no aumento da neurotransmissão dopaminérgica mimetizam aspectos comportamentais e neuroquÃmicos caracterÃsticos da esquizofrenia. Psicoestimulantes, como a anfetamina, são utilizados com esta finalidade, pois aumentam os nÃveis de dopamina extracelular nas vias mesocorticolÃmbica e mesoestriatal. As limitações da manipulação direta do sistema dopaminérgico nos modelos animais incentivam abordagens complementares. O óxido nÃtrico (NO), um neurotransmissor atÃpico que inibe a recaptação de dopamina e estimula sua liberação, parece modular comportamentos controlados pelo sistema dopaminérgico. O teste de inibição pré-pulso revela uma deficiência no filtro sensório-motor, verificada em esquizofrênicos ou após tratamentos com psicotomiméticos, podendo ser prevenida pela inibição do NO. Esta revisão apresenta evidências da interação do NO com o sistema dopaminérgico em modelos para o estudo da esquizofrenia como uma nova ferramenta de investigação desta patologia.<br>Experimental models based on the increase of dopaminergic neurotransmission mimic behavioral and neurochemical schizophrenia-like aspects. Psychostimulants, as amphetamine, are used with this purpose because they increase extracellular dopamine levels in mesocorticolimbic and mesostriatal pathways. The limitations of direct manipulation uniquely based on the dopamine system in animal models have encouraged the use of new approaches. Nitric oxide (NO), an atypical neurotransmitter which inhibits dopamine reuptake and stimulates its release, seems to modulate dopamine-controlled behaviors. The prepulse inhibition test reveals deficits on the sensorimotor filter found in schizophrenics or after psichotomimetic treatments. This review presents evidences for the interaction between NO and DA systems on schizophrenia models as a new tool for the investigation of this pathology
Influence of external factors on the preservation of human nervous tissue for histological studies: review article
Neuropathological studies are crucial for the new knowledge on pathophysiology and treatment of neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. The postmortem brain tissue processing method directly impacts on both the appropriate integrity and the biomolecules detection by different histological and molecular biology techniques. In this review we will discuss topics on the influence of some external factors on the preservation of the brain tissue for histological studies (histochemistry and immunohistochemistry), such as factors either prior or after the death, and the chosen method for the preservation of nervous tissue. By means of a specific example, we propose a strict record of various conditions involved in the method of preservation of nervous tissue, and its correlation with variables that measure the quality of the histological sample as markers of preservation of biological material for further studies
Effects of aging on nitrergic neurons in human striatum and subthalamic nucleus
Nitric oxide (NO) is a major neurotransmitter associated with motor control in basal ganglia. Movement disorders, as essential tremor and Parkinson’s disease, are more prevalent on aged individuals. We investigated the effects of aging on neuronal density and diameter/area of nitrergic neurons in samples of striatum (caudate and putamen) and subthalamic nucleus of 20 human brains from normal subjects, stained by histochemistry for NADPH-diaphorase and immunohistochemistry for neuronal NO synthase. Our data showed aging does not modify the neuronal density and size of nitrergic neurons in striatum and subthalamic nucleus. These findings suggest a lack of association between aging and morphologic changes on nitrergic neurons
Ultrastructural and biochemical changes of the medial pterygoid muscle induced by unilateral exodontia
The aim of the present study was to investigate the histological, biochemical and ultrastructural effects of occlusal alteration induced by unilateral exodontia on medial pterygoid muscle in guinea pigs, Cavia porcellus. Thirty (n = 30) male guinea pigs (450 g) were divided into two groups: experimental-animals submitted to exodontia of the left upper molars, and sham-operated were used as control. the duration of the experimental period was 60 days. Medial pterygoid muscles from ipsilateral and contralateral side were analyzed by histological (n = 10), histochernical (n = 10), and ultrastructural (n = 10) methods. the data were submitted to statistical analysis. When the ipsilateral side was compared to the control group, it showed a significantly shorter neuromuscular spindle length (P 0.05). in the contralateral side, the neuromuscular spindles showed significantly shorter length (P < 0.05), the fibers reflected a higher oxidative capacity, the blood capillaries showed endothelial cell emitting slender sprouting along the pre-existing capillary, and significantly higher blood capillary surface density, and volume density (V-v = 89% Mann-Whitney test, P < 0.05). This finding indicated a complex morphological and functional medial pterygoid muscle adaptation to occlusal alteration in this experimental model. Considering that neuromuscular spindles are responsible for the control of mandibular positioning and movements, the professional should consider if these changes interfere in the success of clinical procedures in medical field involving stomatognathic structures. (c) 2007 Elsevier B.V. All rights reserved.Univ São Paulo, Fac Dent, São Paulo, BrazilUniversidade Federal de São Paulo, Fac Med, São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, São Paulo, BrazilUniv State Rio de Janeiro UERJ, Biomed Ctr, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Fac Med, São Paulo, BrazilWeb of Scienc
Trigeminal nitric oxide synthase expression correlates with new bone formation during distraction osteogenesis
Nitric oxide synthase (NOS) has been reported to be involved with both bone healing and bone metabolism. The aim of this study was to test the null hypothesis that there is no correlation between new bone formation during mandibular distraction osteogenesis and NOS expression in the trigeminal ganglion of rats. Newly formed tissue during distraction osteogenesis and trigeminal NOS expression measured by the NADPH-diaphorase (NADPH-d) reaction were evaluated in 72 male Wistar rats by histomorphometric and histochemical methods. In animals submitted to 0.5 mm/day distraction osteogenesis, the percentage of bone tissue was higher in the basal area of the mandibles compared with the center and significantly increased through the experimental periods (P < 0.05). At the sixth postoperative week, the difference in bone formation between the continuous and acute distraction osteogenesis groups was the highest. Significant correlation between new bone formation by distraction osteogenesis and NADPH-d-reactive neurons was found, varying according to neuronal cell size (r = -0.6, P = 0.005, small cells strongly stained; r = 0.5, P = 0.018, large cells moderately stained). The results suggest that NOS may play a role in the bone healing process via neurogenic pathways, and the phenomenon seems to be neuronal cell morphotype-dependent. Further studies are now warranted to investigate the mechanistic link between the expression of trigeminal NOS and mandibular new bone formation by distraction osteogenesis