Topological and histological description of preoptic area and hypothalamus in cardinal tetra Paracheirodon axelrodi (Characiformes: Characidae)

Topological and histological descriptions of the preoptic area and hypothalamus of the cardinal tetra Paracheirodon axelrodi were performed. Standard histological paraffin sections were used and stained with Nissl technique, and plastic sections for high-resolution optic microscopy (HROM). The preoptic area showed some differences related to the location of the magnocellular preoptic nucleus (PM) and the size of the neurons in this region, as they were the biggest in all the preoptic area. Additionally, within the preoptic area, the different structures that comprise the organum vasculosum of the lamina terminalis (OVLT) were identified and characterized. The hypothalamus could be subdivided in three regions - the ventral, the dorsal and the caudal hypothalamic regions - neuron morphology, size and staining pattern were similar in all of them.(AU)

ESUMEN Se realizó la descripción topológica e histológica del área preóptica e hipotálamo en el Neón cardenal Paracheirodon axelrodi. Se usaron cortes obtenidos con tecnicas histológicas estándar, coloreados con técnica de Nissl y secciones en resina con microscopía óptica de alta resolución (MOAR). El área preóptica muestra algunas diferencias relacionadas con la localización del núcleo preóptico magnocelular (PM) y el tamaño de algunas neuronas en esta región, puesto que estas eran las más grandes de toda el área preoptica. Adicionalmente, dentro del área preóptica, fue posible identificar y caracterizar las diferentes estructuras que componen el órgano vasculoso de la lámina media (OVLM). El hipotálamo puede sudividirse en tres zonas: la zona hipotalámica ventral, la zona hipotalámica dorsal y la zona hipotalámica caudal. La morfología de las neuronas de los núcleos que comprenden las diferentes zonas del hipotálamo tiene tamaño, forma y coloración similar.(AU)

Results From Colombia's 2016 Report Card on Physical Activity for Children and Youth.

BACKGROUND: Physical activity (PA) is vital to the holistic development of young people. Regular participation in PA is associated with substantial benefits for health, cognitive function, and social inclusion. Recognizing the potential of PA in the context of the current peace process in Colombia, the purpose of this article is to present the methodology and results of Colombia's second Report Card on PA for children and youth. METHODS: A group of experts on PA graded 14 PA indicators based on data from national surveys and policy documents. RESULTS: National and departmental policy indicators received a grade of B, while organized sport participation, overweight, obesity, community influence, and nongovernment initiatives indicators received a grade of C. Overall PA levels, active transportation, sedentary behaviors, and school influence received a grade of D. Active play, low physical fitness, and family influence received an Incomplete grade. CONCLUSIONS: PA levels are low and sedentary behaviors are high in Colombian children and youth, with notable geographic differences. A broad policy framework translated into specific actions could provide unique opportunities to bridge the gap between knowledge and practice, and contribute to social integration goals in a postconflict setting.

Rainbow trout (Oncorhynchus mykiss) fry initiation in closed water recirculation systems / Iniciación de alevinos de trucha arcoíris (Oncorhynchus mykiss) en sistemas cerrados de recirculación de agua / Iniciação de alevinos de truta arco-íris (Oncorhynchus mykiss) em sistemas fechados de recirculação de água

Background: rainbow trout is widely accepted for human consumption worldwide, however, its culture requires large quantities of high quality water. Objective: the aim of this study was to evaluate growth and survival of rainbow trout fry cultured in closed water recirculation systems (CRS). Methods: three sequential experiments were conducted, each with three CRS consisting of a fish tank, a gravel bio-filter, a water pump and aeration pumps. Fifty rainbow trout fry were placed in each system and fed with 45% protein pellets. Physicochemical and fish growth parameters were measured for each system at days 1, 15, and 30. Results: water parameters were maintained within normal values for the species in all the experiments. Observed fish growth was similar or greater than previously reported. Survival was lower, mainly due to the presence of Ich in some of the cultures. Although total biomass increase was small due to the low stocking density, condition factor and food conversion were within reported values. Conclusion: this study demonstrates that simple recirculation systems with a very small amount of water can be used for rainbow trout initiation.

Antecedentes: la trucha es una especie de consumo de amplia aceptación a nivel mundial. Sin embargo, su cultivo requiere de la utilización de grandes cantidades de agua de muy buena calidad. Objetivo: el principal objetivo de este trabajo fue el de evaluar el crecimiento y supervivencia de alevinos de trucha arcoíris cultivados en sistemas cerrados de recirculación de agua (CRS). Métodos: se llevaron a cabo tres experimentos secuenciales, cada uno de ellos con tres CRS que estaban compuestos de un tanque de peces, un biofiltro en grava, una bomba de agua y bombas de aireación. En cada sistema se sembraron 50 alevinos de trucha arcoíris que se alimentaron con concentrado al 45% de proteína. Los días 1, 15 y 30 de cultivo se tomaron parámetros fisicoquímicos del agua y parámetros de crecimiento de los peces para cada sistema. Resultados: en general, en todos los experimentos se mantuvieron parámetros del agua dentro de los reportados para la especie. El crecimiento fue similar o mayor a lo observado en otros trabajos. La supervivencia fue menor, debido principalmente a un brote de Ich en algunos cultivos. El incremento en biomasa total fue bajo ya que la densidad de siembra fue baja; el factor de condición y la conversión alimenticia fueron similares a valores ya descritos. Conclusión: de acuerdo con los resultados obtenidos en este trabajo, los sistemas de recirculación simples pueden ser utilizados para la iniciación de trucha arcoíris, con un nivel de utilización de agua muy bajo.

Antecedentes: a truta é uma espécie de ampla aceitação a nível mundial. No entanto, o seu cultivo requer a utilização de grandes quantidades de água de boa qualidade. Objetivo: avaliar o crescimento e a sobrevivência de alevinos de truta arco-íris cultivados em sistemas fechados de recirculação de água (CRS). Métodos: Foram realizados três experimentos sequenciais, cada um com três CRS. Os CRS estavam constituídos por um tanque com peixes, um biofiltro em cascalho, uma bomba de água e bombas de aeração. Em cada sistema foram cultivados 50 alevinos de truta arco-íris que se alimentaram com uma ração de 45% de proteína. Os dias de cultivo 1, 15 e 30 foram medidos os parâmetros físico-químicos da água e os parâmetros de crescimento dos peixes em cada sistema. Resultados: em todos os experimentos, os parâmetros da água estiveram dentro dos reportados para a espécie. O crescimento foi semelhante ou maior ao observado em outros estudos. A supervivência foi menor devido ao surto de Ich em alguns cultivos. O incremento em biomassa total foi baixo porque a densidade de alevinos também foi baixa. O fator de condição e a conversão alimentar foram semelhantes aos valores descritos para a espécie. Conclusão: de acordo com os resultados deste trabalho, os sistemas de recirculação simples podem ser usados para a iniciação da truta arco-íris com um menor consumo de água.

Histología y morfometría del ojo del pez dulceacuícola Paracheirodon axelrodi (Characiformes: Characidae)

Histology and morphometry of the eye in the freshwater Paracheirodon axelrodi (Characiformes: Characidae). The visual system of Teleost fishes has a wide range of adaptations. The eye has suffered modifications, mainly towards better sensitivity and visual resolution according to specific environmental conditions. In that way, this organ is so important for survival. In spite of being the most commercialized Orinoquía species, and one of the most important ornamental fish worldwide, there are almost no studies on the communication systems of P. axelrodi (including vision). We studied the eye in ten individuals of P. axelrodi, with a mean total length of 2.7 cm (SD= 0.2, n= 20). We measured eye relative size (TRO) after sacrifice. Heads were processed for hematoxylin-eosin, and 8 μm thick sections were obtained. Images were digitalized for histological identification and morphometrics. The relation between TRO and body length was 9.8% (SD= 1.1, n= 20); lens was spherical with a relative size of 64.3% (SD= 4.9, n= 20). Rete mirabilis choroid was composed mainly by capillaries, while sclera was composed of cartilaginous tissue. Retina with eight layers and two membranes. An areae centrales was observed in the posterior retina. Iris covered by a simple cubic epithelium. Cornea of endothelial tissue with two membranes. Pupil almost circular, with a naso-caudal elongation. Measures of retina thickness were as follows: lateral retina 144.5 μm (SD= 5.4, n= 20), temporal retina 210.4 μm (SD= 14.8, n= 20). Lens measurements were: dorso- ventral 759.6 μm (SD= 31.7, n= 20), antero-posterior 763.4 μm (SD= 30.7, n= 20). Cornea thickness was 27.6 μm (SD= 4.3, n= 20); iris thickness was 18.9 μm (SD= 1.9, n= 20); rete mirabilis choroid 22.2 μm (SD= 3.2, n= 20) and sclera: 15.9 μm (SD= 1.2, n= 20). This species has a typical Teleost eye conformation. The retina was thicker in the posterior area, probably related to the presence of neuron groups. This modification allows for a better sharpness and visual resolution. The TRO, areae centrales in the retina, and thin cornea, suggests the need of a well developed visual system resulting from a predatory diet. Rev. Biol. Trop. 57 (4): 1107-1118. Epub 2009 December 01.

El pez dulceacuícola P. axelrodi es de gran importancia comercial en la Orinoquía Colombiana y a nivel mundial, pero carece de estudios acerca de su visión. Se utilizaron diez individuos, con longitud total promedio de 2.7 cm (SD= 0.2, n= 20). Se realizaron cortes a 8 μm y se tiρeron con H-E. El tamaρo relativo del ojo es 9.8% (SD= 1.1, n= 20); el cristalino tiene un tamaρo relativo de 64.3% (SD= 4.9, n=20). Una esclerótica con tejido cartilaginoso. La retina está constituida por ocho capas y dos membranas, hay areae centrales en la zona posterior, por lo tanto tiene mayor espesor que la zona lateral. El espesor promedio de las estructuras es: retina lateral: 144.5 μm (SD= 5.4, n= 20), retina temporal: 210.4 μm (SD= 14.8, n= 20); cristalino (esfιrico): dorso-ventral 759.6 μm (SD= 31.7, n= 20) y antero- posterior 763.4 μm (SD= 30.7, n= 20) y cσrnea: 27.6 μm (SD= 4.3, n= 20). El tamaρo relativo del ojo, relacionado con la presencia de areae centrales y una córnea delgada, muestra las necesidades visuales del neón cardenal (cazador) para adaptarse al hábitat, lo que hace necesario tener un sistema visual desarrollado que le permita tener mejor sensibilidad y resolución visual.

[Histology and morphometry of the in the freshwater Paracheirodon axelrodi (Characiformes: Characidae)]. / Histología y morfometría del ojo del pez dulceacuícola Paracheirodon axelrodi (Characiformes: Characidae).

The visual system of Teleost fishes has a wide range of adaptations. The eye has suffered modifications, mainly towards better sensitivity and visual resolution according to specific environmental conditions. In that way, this organ is so important for survival. In spite of being the most commercialized Orinoquia species, and one of the most important ornamental fish worldwide, there are almost no studies on the communication systems of P. axelrodi (including vision). We studied the eye in ten individuals of P. axelrodi, with a mean total length of 2.7 cm (SD = 0.2, n = 20). We measured eye relative size (TRO) after sacrifice. Heads were processed for hematoxylin-eosin, and 8 microm thick sections were obtained. Images were digitalized for histological identification and morphometrics. The relation between TRO and body length was 9.8% (SD= 1.1, n= 20); lens was spherical with a relative size of 64.3% (SD = 4.9, n = 20). Rete mirabilis choroid was composed mainly by capillaries, while sclera was composed of cartilaginous tissue. Retina with eight layers and two membranes. An areae centrales was observed in the posterior retina. Iris covered by a simple cubic epithelium. Cornea of endotelial tissue with two membranes. Pupil almost circular, with a naso-caudal elongation. Measures of retina thickness were as follows: lateral retina 144.5 microm (SD = 5.4, n = 20), temporal retina 210.4 microm (SD = 14.8, n = 20). Lens measurements were: dorso-ventral 759.6 microm (SD = 31.7, n = 20), antero-posterior 763.4 microm (SD = 30.7, n = 20). Cornea thickness was 27.6 microm (SD = 4.3, n = 20); iris thickness was 18.9 microm (SD = 1.9, n = 20); rete mirabilis choroid 22.2 microm (SD = 3.2, n = 20) and sclera: 15.9 microm (SD = 1.2, n = 20). This species has a typical Teleost eye conformation. The retina was thicker in the posterior area, probably related to the presence of neuron groups. This modification allows for a better sharpness and visual resolution. The TRO, areae centrales in the retina, and thin cornea, suggests the need of a well developed visual system resulting from a predatory diet.

Ultrastructural description of rabies virus infection in cultured sensory neurons.

Primary cultures were made from adult mouse spinal ganglia for depicting an ultrastructural description of rabies virus (RABV) infection in adult mouse sensory neuron cultures; they were infected with rabies virus for 24, 36, and 48 h. The monolayers were processed for transmission electron microscopy and immunochemistry studies at the end of each period. As previously reported, sensory neurons showed great susceptibility to infection by RABV; however, in none of the periods evaluated were assembled virions observed in the cytoplasm or seen to be associated with the cytoplasmic membrane. Instead, fibril matrices of aggregated ribonucleoprotein were detected in the cytoplasm. When infected culture lysate were inoculated into normal animals via intra-cerebral route it was observed that these animals developed clinical symptoms characteristic of infection and transmission electron microscopy revealed assembled virions in the cerebral cortex and other areas of the brain. Sensory neurons infected in vitro by RABV produced a large amount of unassembled viral ribonucleoprotein. However, this intracellular material was able to produce infection and virions on being intra-cerebrally inoculated. It can thus be suggested that the lack of intracellular assembly in sensory neurons forms part of an efficient dissemination strategy.

Ultrastructural description of rabies virus infection in cultured sensory neurons

Primary cultures were made from adult mouse spinal ganglia for depicting an ultrastructural description of rabies virus (RABV) infection in adult mouse sensory neuron cultures; they were infected with rabies virus for 24, 36, and 48 h. The monolayers were processed for transmission electron microscopy and immunochemistry studies at the end of each period. As previously reported, sensory neurons showed great susceptibility to infection by RABV; however, in none of the periods evaluated were assembled virions observed in the cytoplasm or seen to be associated with the cytoplasmic membrane. Instead, fibril matrices of aggregated ribonucleoprotein were detected in the cytoplasm. When infected culture lysate were inoculated into normal animals via intra-cerebral route it was observed that these animals developed clinical symptoms characteristic of infection and transmission electron microscopy revealed assembled virions in the cerebral cortex and other areas of the brain. Sensory neurons infected in vitro by RABV produced a large amount of unassembled viral ribonucleoprotein. However, this intracellular material was able to produce infection and virions on being intra-cerebrally inoculated. It can thus be suggested that the lack of intracellular assembly in sensory neurons forms part of an efficient dissemination strategy.

Agricultura y desarrollo sostenible

Con base en la valiosa y calificada información contenida en Agricultura y Desarrollo Sostenible, el Dr. Zeballos plantea al lector interesado, funcionario público , burócrata de organismo internacional y al agricultor pequeño o grande, el desafíio de proponer y poner en práctica políticas y estrategias que sin dejar de aceptar la idea de la centralidad de los recursos naturales compatibles con las ventajas comparativas del país y de un Estado inteligente y proveedor de bienes e infraestrucutura pública y protección social, promuevan de manera sostenible, mayores niveles de crecimiento economico y desarrollo humano

Studying neurotrophin antiviral effect on rabies-infected dorsal root ganglia cultures.

Neurotrophin (NT)-induced modulation of rabies virus adsorption, transcription, and replication were analyzed in adult mouse dorsal root ganglia cultures. Different types of nerve growth factor and NT-3 treatment were tested before infection (pretreatment), during infection (transtreatment) and after withdrawing the viral inoculum (post-treatment). NT pretreatment for 4 days prior to infection produced a significant increase in the quantity of virus adsorbed into cultures and a concomitant increase in genomic viral RNA as measured by real time polymerase chain reaction (PCR). NT pretreatment triggered increased expression of two rabies virus receptors (NCAM and p75NTR); however, no increase in rabies virus transcription and expression could be observed. By contrast, NT treatment during and after infection (trans- and post-treatment) induced a strong decrease in the quantity of viral nucleoprotein genomic and messenger nucleoprotein RNAs. These findings suggested that NT had an intrinsic inhibitory effect on rabies virus infection, which was not counterbalanced by NTs' rabies virus receptor-enhancing property and viral uptake. Adult mouse dorsal root ganglion cultures can be regarded as being a useful model for detecting therapeutic targets and evaluating experimental antiviral drugs.

Differential use of the nicotinic receptor by rabies virus based upon substrate origin.

To determine the role that the neuronal nicotinic acetylcholine receptor plays in the adsorption process of rabies virus (RV), adult dorsal root ganglion dissociated cultures were exposed to nicotinic agonists before being inoculated. The fixed strain of RV Challenge Virus Standard-11 (CVS-11) was used after being passaged in two different ways, in baby hamster kidney (BHK) cells and in adult mouse brain (MB). Carbachol and nicotine reduced the percentage of CVS-MB infected neurons, yet none of the agonists tested changed the proportion of CVS-BHK infected neurons. This result suggests that the RV phenotype changes depending on its replication environment and neuronal nicotinic acetylcholine receptors are preferentially used for infection by RV strains adapted to adult mouse brain but not to fibroblasts.

Relationship between functional deficiencies and the contribution of myelin nerve fibers derived from L-4, L-5, and L-6 spinolumbar branches in adult rat sciatic nerve.

The distribution and relative intrafascicular contribution of myelin fibers derived from spinal segments L-4 to L-6 were analyzed in adult rat sciatic nerve and its main branches, using 200-kDa neurofilament subunit immunodetection in previously injured nerve sections in the L-4 or L-5 spinal branch or both. These branches' functional contribution was evaluated 16 days after the injury, using the method of J. Bain, S. Mackinnon, and D. Hunter (1988, Plast. Reconstr. Surg. 83: 129-136). A common topographic intrafascicular distribution was found in 69% of cases, with notable segregation of L-4 and L-5 fibers and a random distribution for L-6 fibers. At sciatic nerve main branch level, L-4 contributes almost entirely to the peroneal nerve, L-5 to the tibial nerve, and L-6 and other branches to the sural nerve. After injury to L-4, a significant reduction in peroneal nerve functional index (PFI) was observed, as was a reduction in print length (PL). Injury to L-5 caused a significant reduction in the sciatic (SFI) and tibial (TFI) functional nerve indices, an increase in PL, and a reduction in the spread between opposite toes (TS). Finally, transection of both L-4 and L-5 was followed by a significant reduction in all functional indices measured, an increase in PL, and a reduction in intermediate toe (ITS) and opposite toe spread (TS). The results indicate a direct relationship between the distribution and contribution of the spinal nerve fibers forming the sciatic nerve and the alteration in functional indices for sciatic, tibial, and peroneal nerves.

Schwann cell-enriched cultures from adult human peripheral nerve: a technique combining short enzymatic dissociation and treatment with cytosine arabinoside (Ara-C).

Attempts to design the nerve cellular prostheses have focused on the production of autologous Schwann cells expanded in vitro as the essential component in the regeneration process of injured peripheral nerves. To obtain human Schwann cells of high quality we tested a short enzymatic dissociation protocol that optimized cellular viability levels. We also assessed patterns of bromodeoxyuridine (BrdU) incorporation in both Schwann cells and fibroblasts in the presence or absence of the antimitotic Ara-C, an enrichment option for adult human Schwann cell cultures. The Ara-C treated cultures showed a significantly higher Schwann cell percentage (95%), compared with that obtained in the absence of Ara-C (70%), indicating that this antimitotic acts to eliminate fibroblasts in each one of the applied pulses (four pulses). However, we have observed that the use of this antimitotic during prolonged periods of time produced a cumulative effect causing Schwann cell cytotoxicity. Therefore, we consider that our enzymatic dissociation technique and the application of only two pulses of Ara-C to the cultures are enough to achieve enrichment of adult human Schwann cells in culture.

Receptores para el virus de la rabia / Rabies virus receptors

El virus de la rabia causa una infección en el sistema nervioso que puede provocar la muerte. La patogenia y el neurotropismo de este virus han sido estudiados extensamente con el objeto de explicar el porqué la letalidad de la enfermedad y proponer nuevas alternativas terapéuticas. El proceso de adsorción del virus a la célula blanco se considera un evento que define el neurotropismo del virus. Se piensa que debe existir una molécula en la superficie de las neuronas que une con alta afinidad al virus y da comienzo al proceso infeccioso. Durante los últimos años se han propuesto varias proteínas, carbohidratos y lípidos complejos, como receptores para el virus de rabia y se han hecho nuevas proposiciones de terapia antirreceptor. Además de los gangliósidos y fosfolípidos para los que se ha hallado evidencia sobre su participación en la adsorción del virus de la rabia, hay datos experimentales sobre la participación del receptor nicotínico de acetilcolina, la molécula de adhesión celular neural y el receptor de baja afinidad para neurotrofinas en la infección neuronal. En este artículo se hace una revisión de los datos que sustentan a cada una de las moléculas propuestas, se discuten sus implicaciones para la explicación del neurotropismo del virus de rabia y la exploración de nuevas terapias antivirales

ATPasa de calcio en el sistema nervioso / Calcium ATPase in the nervous system

La bomba de calcio es una proteína integral de la membrana que regula el calcio libre citoplasmático en concentraciones menores de 0,1 mM. En la mayoría de las células eucarióticas está ubicada en la membrana, en el plasmalema o en organelos como el retículo sarcoendoplásmico y los calciosomas. Su actividad está dada por la hidrólisis de ATP, la concentración del ion en el citoplasma y por otros factores que regulan como la calmodulina, los fosfolípidos y las proteínas - cinasas. Por diferentes métodos, se ha detectado la ATPasa de calcio y su actividad en el tejido nervioso central y periférico, como en otros tejidos

Anticuerpos aviares: alternativa en producción y diagnóstico / Avian antibodies: an alternative in production and diagnosis

El uso de anticuerpos para investigación y diagnóstico se realiza desde hace varias décadas en todo el mundo. Normalmente, estos anticuerpos se obtienen a partir del suero de mamíferos (roedores, caprinos, equinos, etc.) De acuerdo con el tamaño de huésped, se pueden producir pequeñas o grandes cantidades de suero, haciendo siempre sangrías regulares para su recolección. En los últimos años, se han utilizado cada vez con mayor frecuencia anticuerpos purificados a partir de huevos de gallina inmunizadas, los cuales presentan diferencias con los anticuerpos producidos en mamíferos en su estructura y características fisicoquímicas, pero además, son una alternativa que disminuye el estrés e injuria al huésped y tiene alta productividad y facilidad para su recolección. Se ha informado el uso de estos anticuerpos aviares en ensayos inmunoquímicos, producción de conjugados y en terapéutica con un éxito similar al de los anticuerpos en mamíferos y a un costo menor. En este trabajo, se hace una revisión del tema y se plantean sus posibles usos tanto en investigación y diagnóstico, como en terapia

Contribución de fibras mielínicas provenientes de los nervios espinales lumbares L4, L5 y L6 al nervio ciático de rata adulta y sus ramas principales / Contribution of myelinated fibers from spinal L4, L5 and L6 nerves to the sciatic nerve and its main branches in the adult rat

El nervio ciático de la rata está formado por los nervios espinales (NE) lumbares L4, L5 y L6. Sin embargo, aún no se ha definido el aporte en fibras mielínicas de estos nervios espinales a lo largo del tronco nervioso. En este estudio se transectaron selectivamente los NE L4, L5 y L4-L5. Luego de una semana se disecaron los nervios ciático, tibial, sural y peroneal. Estas muestras se fijaron y procesaron para microscopía óptica y a partir de cortes coloreados con azul de toluidina se contaron las fibras mielínicas degeneradas y normales. L4 contribuyó con fibras mielínicas principalmente al nervio peroneal y L5 a los nervios ciático, tibial y sural. En general, el aporte de L6 fue menor y variable a lo largo del tronco nervioso comparado con las otras dos ramas espinales. Nuestros resultados brindan información valiosa para posteriores estudios que busquen correlacionar la contribución de los nervios espinales que componen el ciático y sus ramas principales con la función de la extremidad inferior.

The rat sciatic nerve is composed by the L4, L5 and L6 lumbar spinal nerves. However, the contribution in myelinated fibers originating from these nerves along this nervous trunk has not yet been defined. In the present study, the L4, L5 and L4-L5 spinal nerves were selectively transected. After one week the sciatic, tibial, sural and peroneal nerves were dissected. These samples were fixed and processed for optical microscopy, and both degenerated and normal myelinated fibers were counted in toluidine blue-stained semi-thin sections. L4 contributed with myelinated fibers mainly to the peroneal nerve, and L5 to the sciatic, tibial and sural nerves. In general, the contribution of L6 was smaller and variable along the nervous trunk in comparison to the other two spinal branches. Our results give key information for further studies looking to correlate the contribution of spinal nerves making part of the sciatic nerve and its main branches with hind limb function.

Subpoblaciones neuronales presentes en el ganglio de la raíz dorsal / Neuronal subpopulations present in the dorsal root ganglion

La función principal de las neuronas del ganglio de la raíz dorsal (GRD) es transmitir la información sensorial desde la periferia hasta el sistema nervioso central. Dos clases de la célula están presentes en el ganglio: las células no neuronales y las neuronales. La heterogeneidad morfológica, fisiológica y bioquímica de la población neuronal permite diferenciarla en subpoblaciones. Morfológicamente, se distinguen tres tipos neuronales (A, B y C) según el tamaño y las características ulraestructurales. Fisiológicamente, hay una relación directa entre el tamaño, el diámetro de las fibras nerviosas y la velocidad con que conducen el impulso nervioso. Finalmente, el uso de marcadores (neuropéptidos, enzimas, receptores, etc.) permite realizar una clasificación bioquímica, que es la más utilizada para estudiar la función neuronal. Este artículo revisa la evidencia experimental sobre el tema de la heterogeneidad neural del GRD y presenta una correlación desde el punto de vista bioquímico y fisiológico en los casos en donde hay información disponible. El estudio de subpoblaciones en este ganglio resulta de bastante interés para investigaciones en neurociencias principalmente en infecciones por virus neurotrópicos, traumatismos del nervio periférico y el estudio de factores neurotróficos, entre otros

Técnica inmunocitoquímica para evaluar la proliferación de células en cultivo por la incorporación de bromodeoxiuridina / Description of an immunocytochemical evaluation technique for in vitro cell proliferation by bromodoxiuridine incorporation

Para evaluar la proliferación in vitro de células, se estandarizó una técnica inmunocitoquímica no radioactiva, fácil de manejar, más rápida y segura que permite detectar la bromodeoxiuridina (BrdU) incorporada en las células que entran en fase S. Durante la estandarización de la ténica inmunocitoquímica con peroxidasa, se usaron varios tipos celulares y se obtuvieron resultados similares. Brevemente, se realiza una incubación BrdU durante 48 horas y luego, se procesa el material celular para una inmunocitoquímica convencional que tiene como paso adicional la desnaturalización del ADN con HCI previa a la incubación con el anticuerpo primario anti-BrdU. Como cromógeno se usó la DAB (diaminobenzidina) o el AEC (aminoetilcarbazol). El procedimiento utilizado permite ver una tinción específica para núcleos en células que entran en fase S y permite evaluar rápidamente el porcentaje de células que están proliferando en el cultivo

Cámaras de silicona como injerto nervioso: análisis de la especificidad de regeneración del nervio peroneal o tibial / Silicone chamber like nervious graft: analysis of the regeneration specificity of the tibial or peroneal nerve: experimental study in rats

en el presente estudio se creó un modelo experimental en el cual el nervio ciatico de 30 ratas adultas fue seccinado y posteriormene suturado a un tubo de silicona. A los tres y seis meses de regeneración la rama peroneal o tibial fue seccionada proximal al tubo. Se esperó la degeneración Walleriana y luego se tomaron tres niveles para los estudios histológicos e inmunohistoquímicos: la parte media de la cámara y los nervios del peroneal y tibial distales. Se contaron las fibras y se analizó la contribución específica de cada nervio en el extremo distal. Los datos se analizaron tomando como variables la contribución y distribución de las fibras. En este trabajo se logró demostrar una regeneración inespecífica en el extremo distal, encontrandose fibras provenientes de cualquiera de los dos nervios.