Bovine central nervous system development / Desenvolvimento do sistema nervoso central de bovinos

Central nervous system (CNS) development researches are extremely important to the most common congenital disorders and organogenesis comprehension. However, few studies show the entire developmental process during the critical period. Present research can provide data to new researches related to normal development and abnormalities and changes that occur along the CNS organogenesis, especially nowadays with the need for preliminary studies in animal models, which could be used for experimental research on the influence of viruses, such as the influence of Zika virus on the development of the neural system and its correlation with microcephaly in human newborns. Then, present study describes CNS organogenesis in cattle according to microscopic and macroscopic aspects, identifying structures and correlating to gestational period. Fourteen embryos and nine bovine fetuses at different ages were collected and analyzed. All individuals were measured in order to detect the gestational period. Bovine embryo at 17 days age has its neural tube, cranial neuropore, caudal neuropore and somites developed. After 24 days of development, were observed in cranial part of neural tube five encephalic vesicles denominated: telencephalon, diencephalon, mesencephalon, metencephalon and myelencephalon. In addition, the caudal part of neural tube was identified with the primitive spinal cord. The primordial CNS differentiation occurred from 90 to 110 days. The five encephalic vesicles, primordial spinal cord and the cavities: third ventricule, mesencephalic aqueduct, fourth ventricle and central canal in spinal cord were observed. With 90 days, the main structures were identified: (1) cerebral hemispheres, corpus callosum and fornix, of the telencephalon; (2) interthalamic adhesion, thalamus, hypothalamus and epythalamus (glandula pinealis), of the diencephalon; (3) cerebral peduncles and quadruplets bodies, of the mesencephalon; (4) pons and cerebellum, of the metencephalon; (5) medulla oblongata or bulb, of the myelencephalon; and (6) spinal cord, of the primitive spinal cord. After 110 days of gestation, the five encephalic vesicles and its structures were completely developed. It was noted the presence of the spinal cord with the cervicothoracic and lumbossacral intumescences. In summary, the results describes the formation of the neural tube from the neural plate of the ectoderm, the encephalic vesicles derived from the neural tube and subsequent structural and cavities subdivisions, thus representing the complete embryology of the central nervous system.(AU)

Os estudos que descrevem o desenvolvimento do sistema nervoso central (SNC) são de suma importância para compreensão da organogênese e identificação dos prováveis eventos que resultam em malformações congênitas. Estes dados podem subsidiar novas pesquisas relacionadas ao desenvolvimento normal, e interpretação de malformações e alterações que ocorrem ao longo da organogênese do SNC, considerando neste momento a necessidade de estudos preliminares em modelos animais, os quais poderiam ser utilizados para pesquisas experimentais sobre a influência de agentes infecciosos como o Zika vírus, no desenvolvimento do sistema nervoso e suas relações com a microcefalia em humanos recém-nascidos. O presente estudo teve como objetivo descrever os aspectos morfológicos macro e microscópicos da organogênese do SNC de bovinos, buscando correlacionar os achados morfológicos com a idade gestacional. Todos os animais foram mensurados para detectar o período gestacional. Foram coletados e analisados 14 embriões e nove fetos de bovinos de diferentes idades gestacionais. No embrião bovino a partir do décimo sétimo dia de gestação, encontra-se a formação do tubo neural, o neuroporo cranial e neuroporo caudal, e formação dos somitos. Após 24 dias de desenvolvimento, são observadas na parte cranial do tubo neural cinco vesículas encefálicas denominadas: telencéfalo, diencéfalo, mesencéfalo, metencéfalo e mielencéfalo; e na parte caudal do tubo neural, encontra-se a medula espinhal primitiva. Entre 90 a 110 dias de gestação, observa-se a total diferenciação das cinco vesículas do SNC. Com 90 dias, são identificas as principais estruturas: (1) do telencéfalo, os hemisférios cerebrais, corpo caloso e fórnix; (2) do diencéfalo, a aderência intertalâmica, tálamo, hipotálamo e epitálamo (glândula pineal); (3) do mesencéfalo, os pedúnculos cerebrais e os corpos quadrigêmios; (4) do metencéfalo, a ponte e o cerebelo; (5) do mielencéfalo, a medula oblonga (ou bulbo); e (6) da medula espinhal primitiva, a medula espinhal. Após 110 dias, as cinco vesículas encefálicas e as suas subdivisões se encontram completamente desenvolvidas. Notou-se a presença da medula espinhal com as intumescências cervicotorácica e lombossacral. Em resumo, os resultados demonstram a formação do tubo neural a partir da placa neural do ectoderma, as vesículas encefálicas provenientes do tubo neural e posteriormente as subdivisões das estruturas e das cavidades, que representam a completa embriologia do sistema nervoso central.(AU)

Desarrollo de la médula espinal de salmón (Salmo salar) durante el período post-eclosional / Development of spinal cord of the salmon (Salmo salar) during the period post eclosional

En este estudio se describe el desarrollo post-eclosional de la médula espinal del salmón. Salmo salar. Se utilizaron 200 alevines recién eclosionados, los que fueron cultivados en el Centro de Estudios Acuícolas de la Universidad de Chile. Las condiciones ambientales de cultivo fueron de un 90% de saturación de oxigeno. La temperatura ambiental se mantuvo en 7°C. A los días 1, 3, 5 7 ds post-eclosión, 50 alevines por grupo etario fueron anestesiados y sacrificados por exposición a 5% Benzocaina diluida en agua (Kalmagin 20®, Farquímica). Posteriormente fueron fijados en formalina tamponada al 10% y procesados mediante técnica histológica. Para cada alevín se tomaron a nivel de la aleta dorsal un total de 40 cortes coronales seriados de 5µm de grosor, los que fueron procesados de acuerdo a las técnicas Cresil violeta. La cuantificación neuronal se realizó sobre imágenes microscópicas mediante el método del disector. Los resultados obtenidos se sometieron a una prueba de Coeficiente de Kurtosis con el propósito de analizar el grado de concentración que presentan los valores alrededor de la zona central de la distribución. La médula espinal de los alevines de 1 día es poco diferenciada. En los alevines de 3, 5 y 7 días se diferencian gradualmente las neuronas de la sustancia gris, pero no presenta la distribución característica en forma de "Y" invertida del salmón adulto. El número de neuronas aumenta desde 67+1.7 en el día 1 hasta 88+2.1 en el día 7. Esta observación se puede relacionar con la ausencia de movimientos natatorios de los peces durante los primeros días ya que estos caen sobre la gravilla al fondo de las bateas. Un factor determinante en la adquisición de la morfología de la médula espinal es el inicio de los movimientos natatorios, lo que ocurre aproximadamente al quinto día post-eclosión. La actividad motriz activa permite que las neuronas de la médula espinal sean reclutadas y se formen y activen las redes neurales, permaneciendo finalmente los circuitos más eficientes. El aumento del número de neuronas se puede explicar por neurogénesis post-eclosión, como ocurre en otros teleósteos. Este estudio indica que al momento de la eclosión, el sistema nervioso está muy indiferenciando, y que durante las primeras semanas de vida del alevín ocurre la diferenciación de las neuronas y neurogénesis. Este conocimiento es muy importante debido a que en las pisciculturas se cuidan las ovas, y se descuida la fase del alevinaje en la creencia que los tejidos están constituidos.

We describe the development of the spinal cord during the post eclosion period of the salmon (Salmo salar).We used a total of 200 newly hatched fry grown in the Aquaculture Research Center of the Universidad de Chile. Environmental conditions were of 90% oxygen saturation. Ambient temperature was maintained at 7° C. At days, 1, 3, 5 and 7, post-hatching, 50 fry were anesthetized and sacrificed by exposure to 5% benzocaine diluted in water, (Kalmagin 20 ®, Farquímica). They were then fixed in 10% buffered formalin and processed by histological technique. For each juvenile a total of 40 serial coronal sections of 5µm were taken at the level of the dorsal fin, which were then processed according to cresyl violet techniques.Neuronal quantitation was performed on microscopic images by dissector method. The results obtained were subjected to coefficient Kurtosis test in order to analyze the degree of concentration of values around the central distribution area.The spinal cord of the one-day fry is poorly differentiated. In fry of 3, 5 and 7 days neurons are gradually differentiated, they do not however present the characteristic neuronal distribution inverted "Y" of the adult salmon. The number of neurons increases from 67±1.7 on day one, to 88±2.1 on day 7.This observation may be related to the absence of fish swimming movements during days one and three as these fall on the gravel at the bottom of the trays. A determining factor in the acquisition of the morphology of the spinal cord is the start of swimming movements, which occur at around the fifth day post-hatching.Active motor activity allows spinal cord neurons to be recruited and form to activate neural networks, to remain finally in the most efficient circuits. Increasing the number of neurons can be explained by post-hatching neurogenesis as in other teleosts.This study indicates that at the time of hatching, the nervous system is very undifferentiated and that neuron differentiation and neurogenesis occur during the first weeks of life. This knowledge is very important as fish farms take care of eggs, neglecting the nursery stage in the belief that tissues are formed.

El tubo neural y el saco vitelino durante el primer trimestre: articuladores del desarrollo embrionario temprano / Neural axis and yolk sac during the first trimester of pregancy: articulators of early embryonic growth

El conocimiento del desarrollo humano a través del ultrasonido ha postergado el conocimiento de todo aquello que no sea el feto. Sólo en revistas muy especializadas de las ciencias básicas se incorpora el estudio de la placenta, el cordón o los anexos embrionarios como el saco vitelino. El embrión humano se desarrolla durante las primeras semanas en un complejo sistema de vesículas que le permiten sobrevivir y diferenciarse en una etapa en que sólo depende de los aportes del ultrafiltrado del plasma materno alojados en el saco corial y transportados por saco y conducto vitelino. Se muestra en examen ultrasonográfico de primer trimestre, la relación que existe entre la diferenciación inicial del tubo neural y el saco vitelino.

Body ache and pain in school children associated with school bag carriage in Multan - Pakistan

In Pakistan anecdotal evidence of shoulder, back pain in school children is alarming but no scientific studies have been carried out yet. This study was carried out to find out any association between pain and school bag carriage in students, since almost all school management including public and private in Pakistan putting extra loads on the children in the form of heavy school bags. Children and in the phase of growth and development. So there is continuous endanger of growth and developmental retardation due to growth due to pulling heavy school bags load not only but also some sort of body aches and pains occur. This study was carried at four different schools in Multan. Schools were selected by convenience sampling. Two hundred children between the ages of 11 and 14 years correctly filled out a questionnaire with open ended and closed ended questions. Each child also had his/her body and bag weight measures. In this study, most of the children experienced shoulder and a combination of shoulder and other bodily pain. The majority of the children carried school bags over two shoulders. The type of bag carried was significantly related to pain experienced. A significantly larger number of female students experienced pain. The shoulder and other bodily pain experienced by the students are strongly related to the type of bag and the gender of the children

Pontes de nervos perifericos no auxilio da regeneracao da medula espinhal / Peripheral nerves bridges in aid of spinal cord regeneration

Ao contrario da grande capacidade de regeneracao observada em nervos perifericos, o tecido nervoso central adulto apresenta minima regeneracao apos trauma. Apesar dos rearranjos sinapticos subsequentes ao trauma, lesoes medulares resultam em deficits permanentes. Intervencoes no microambiente neuronal sao necessarias para promover regeneracao de neuronios medulares. Neste trabalho utilizamos pontos de nervos interligando regioes da medula espinhal previamente lesadas, fornecendo assim microambiente favoravel a regeneracao de neuronios centrais...