RESUMO
This study analyzes the temporal-spatial correlation between angio-and corticogenesis in the developing chick optic tectum (OT) by means of NADPH-diaphorase and immunolabeling methods. Qualitative and quantitative parameters were used to analyze a new vessels formation and growth of preexisting ones as a function of time and space...
Assuntos
Embrião de Galinha , Movimento Celular/fisiologia , Neovascularização Patológica/patologia , Proliferação de Células , Sistema Nervoso Central/embriologia , Veias Cerebrais/patologia , Vias Visuais/anatomia & histologia , AnisotropiaRESUMO
The tangential distribution of the striate-peristriate cortical connections in normal, postnatally eye nucleated and congenitally anophthalmic rats, was studied after a single injection of wheat germ agglutinin conjugated with horseradish peroxidase into the striate cortex. The typical normal pattern of separate fields in the peristriate cortex is altered in eye enucleated animals, in such a way that their areal distribution in the cerebral cortex is increased and each field tends to fuse with the adjacent one. This process is more marked in anophthalmic animals, a finding that is in agreement with the notion that ganglion cells exert their influence before the visual pathway is functional
Assuntos
Animais , Ratos , Córtex Cerebral/anatomia & histologia , Retina/anatomia & histologia , Privação Sensorial , Córtex Visual/anatomia & histologia , Anoftalmia , Córtex Cerebral/citologia , Enucleação Ocular , Peroxidase do Rábano Silvestre , Ratos Sprague-Dawley , Córtex Visual/citologia , Vias Visuais/anatomia & histologia , Aglutininas do Germe de TrigoRESUMO
1. The topographic organization of the cortical visual areas in the Cebus monkey and their anatomical connections support the subdivision of the visuaol pathways into ventral and dorsal streams of visual information provessing. 2. We propose that the dorsal stream, as defined by Ungerleider and Mishkin (In: Ingle DJ, Goodale MA and Mansfield RJW (Editors), Analysis of Visual Behavior, MIT Press, Boston, 1982), be subdivided into dorsolateral and dorsomedial streams, which are concerned with different aspects of the processing of motion and spatial perception. 3. The data support the hypothesis of concurrent, modular processing of visual attributes in cortical visual areas in the different streams, and highlight some features of the visual field representation in each area which may reflect functional specialization of these streams. 4. The visual topography is locally disrupted in some cortical areas by the existence of functionally different modules, However, a global visuotopic organization is preserved in most areas. 5. The visuotopic organization may provide the address of space coordinates to integrate information concerning the same retinotopic across different visual areas