Effect of perinatal exposure to monosodium glutamate on the visual cortex of adult albino rats

Monosodium glutamate [MSG], the sodium salt of glutamate, is commonly used as a flavor enhancer in many food preparations. Its use has become controversial because of reports of adverse reaction in people who have eaten foods that contain monosodium glutamate. One of these adverse reactions was the blurring of vision. The aim of this study was to investigate the impact of monosodium glutamate [MSG] on visual cortex of albino rats. A total 20 pregnant female rats were randomly divided into two groups. Control group and treated group which received monosodium glutamate by gastric gavages in a dose of 2 g/kg b.w from late pregnancy until the end of weaning. Offspring of two groups were left until puberty [2 month old pregnancy until the end of weaning. Offspring of two groups were left until puberty [2 month old rats]. The offspring of both groups were sacrificed at 60 days and their visual cortices were prepared for histological examination by light and electron microscope. The results revealed severe neuronal degeneration. The neurons of treated visual cortex contained hyperchromic, pyknotic nuclei. The cytoplasm became vacuolated and contains large lipofuscin pigments. The mitochondria became swollen with indented membrane, the Golgi apparatus were absent with the presence of few rough endoplasmic reticulum and free ribosome. The blood vessels were dilated with the presence of perivascular edema. It is concluded that the oral intake of monosodium glutamate during pregnancy and lactation has degenerating effect on the visual cortex of the raf's offspring

Horizontal projections of area 17 in Cebus monkeys: metric features, and modular and laminar distribution

Metric features and modular and laminar distribution of intrinsic projections of area 17 were studied in Cebus apella. Anterogradely and retrogradely labeled cell appendages were obtained using both saturated pellets and iontophoretic injections of biocytin into the operculum. Laminar and modular distributions of the labeled processes were analyzed using Nissl counterstaining, and/or cytochrome oxidase and/or NADPH-diaphorase histochemistry. We distinguished three labeled cell types: pyramidal, star pyramidal and stellate cells located in supragranular cortical layers (principally in layers IIIa, IIIb alpha, IIIb beta and IIIc). Three distinct axon terminal morphologies were found i.e., Ia, Ib and II located in granular and supragranular layers. Both complete and partial segregation of group I axon terminals relative to the limits of the blobs of V 1 were found. The results are compatible with recente evidence of incomplete segreagation of visual information flow in V 1 of Old and New World primates.

Aparición de espinas en la dendrita apical en neuronas piramidales del área 17 de ratas Wistar en el período de lactancia / The appearance of fendritic spines on the apical dentrites of area 17 pyramidal neurons in suckling Wistar rats

Se cuantificó el número de espinas dendríticas en ratas Wistar lactantes normales. En el presente trabajo se describen cambios del número de espinas dendríticas en las neuronas piramidales de rata durante la lactancia. Fueron usadas 22 camadas de ratas Wistar, después del nacimiento las camadas se ajustaron a 8 críos, se obtuvieron un total de 176 críos. Las camadas fueron sacrificadas diariamente desde el nacimiento (día 0) hasta los 21 días posnatales. Se cuantificó el número de espinas en segmento de 50 micrómetros de las dendritas apicales de las células piramidales de la corteza visual impregnadas con el método de Golgi-Kopsch. Las espinas fueron evidentes a partir del día 9, para los días 14 a 19 de densidad de espinas se incrementa y del día 20 al 21 hay disminución de espinas en las dendritas.

Estudio de las proyecciones comisurales visuales en el marsupial marmosa elegans / Visual cortex study in the marsupial marmosa elegans

Los marsupiales pertenecen a un orden neurológicamente más primitivo que los mamíferos placentados (e.g. roedores). Ellos carecen de cuerpo calloso y es la comisura anterior la principal vía de comunicación interhemisférica. Por esto y con el fin de comparar con roedores, estudiamos el patrón de interconexión hemisférica visual (orígenes y terminales) en Marmosa elegans mediante el uso de HRP combinado con técnicas que delimitan áreas corticales (mielina y Nissl). Los resultados muestran que la marcación se concentra en bandas: una, delimitando el área estriada de la periestriada y otras separando diferentes subregiones en el área estriada que podrían corresponder a representaciones múltiples del campo visual o a regiones que estén procesando en forma modular parte de la información visual. Este patrón complejo de interconexiones tiene aspectos semejantes a aquel descrito para roedores, sugiriendo que existe una organización cortical visual común en marsupiales y roedores, aún cuando filogenéticamente pertenezcan a grupos bastante separados