Comunicação Visual em Ciclídeos

Artigo que trata sobre visão de ciclídeo, envolvendo diversidade, filogenia, etc.
Article that deals with vision cichlid involving diversity, phylogeny, etc.
Artículo que trata de la visión relacionados con la diversidad de cíclidos, filogenia, etc.

Visual communication in East African cichlid fishes : Diversity in a phylogenetic context
Comunicação visual em peixes ciclídeos do leste africano: diversidade em um contexto filogenético.
La comunicación visual en África peces cíclidos del este: la diversidad en un contexto filogenético.

Autores: Karen L. Carleton, Tyrone C. Spady, and Thomas D. Kocher


Para baixar (download), clique aqui.

Células ganglionares de girafa. Ganglion Cell in the Giraffe

Artigo sobre a topografia das células ganglionares de girafa. Trabalho recente este, publicado ano passado.

Article about the topography of ganglion cells of giraffe. This recent work, published last year.

Scene From Above: Retinal Ganglion Cell Topography and Spatial Resolving Power in the Giraffe (Giraffa camelopardalis)

("cena de cima" : Topografia das células ganglionares da retina e poder de resolução espacial na girafa (Giraffa camelopardalis).

Autores: João Paulo Coimbra, Nathan S. Hart, Shaun P. Collin, and Paul R. Manger

Clique aqui para baixar (to download).

  

Distance to Nearest Neighbor as a Measure of Spatial Relationships in Populations / Distância ao Vizinho Mais Próximo como uma medida da Relação Espacial em Populações

Este artigo trata sobre um método estatístico para se Analisar a distribuição de uma população (de células por exemplo) através da Análise do Vizinho mais próximo. Muito interessante ele. Observação: Meu inglês não é tão bom mas acho que já ajuda.

This article deals with a statistical method to analyze the distribution of a population (eg cell) by Analysis of Nearest Neighbor. Very interesting it.). Note: My English is not so good but I think now it helps ..

Distance to Nearest Neighbor as a Measure of Spatial Relationships in Populations (Distância ao Vizinho Mais Próximo como uma medida da Relação Espacial em Populações) .

Autores: Philip J. Clark; Francis C. Evans

Para baixar (to download ), clique aqui:

Regular Mosaics of Large Displaced and Non-Displaced Ganglion Cells in the Retina of a Cichlid Fish / Mosaico Regular de Grandes Células ganglionares deslocadas e não-deslocadas na retina de um peixe ciclídeo.

Regular Mosaics of Large Displaced and Non-Displaced Ganglion Cells in the Retina of a Cichlid Fish.

Mosaico Regular de Grandes Células ganglionares deslocadas e não-deslocadas na retina de um peixe ciclídeo.

Autor: JEREMY E. COOK AND DAVID L. BECKER.

Para baixar(download) , clique aqui e depois clique em arquivo no canto superior da página que vai abri para você fazer o download gratuitamente.

ABSTRACT

Large retinal ganglion cells in the tilapid cichlid fish Oreochromis spilurus (standard length 15-54 mm) were filled with horseradish peroxidase and studied in flatmounts. Three types, with distinct patterns of dendritic stratification, formed spatially independent, nonrandamics. One type (about 0.3% of all ganglion cells) resembled the outer (off) alpha cells of mammals. They were very large, with thick primary dendrites and large, sparsely branched planar trees in the outer part of the inner plexiform layer (IPL). About 300 were arrayed regularly across each retina, their exact number and spacing depending on its size. Their somata were often displaced into the IPL, even where neighbours in the mosaic were orthotopic. Another type (0.8%) resembled the inner (on) alpha cells of mammals. These had slightly smaller somata that were  never displaced and smaller trees in the middle layers of the IPL. About 800 were arrayed uniformly and regularly across each retina. A rarer type (0.06-0.08%) had two planar trees: one forming a coarse mosaic in the outer part of the inner plexiform layer (co-planar with the trees of outer alpha-like cells) and another in the outer plexiform layer. These “biplexiform” cells were smaller and rounder than alpha-like cells and always displaced. The dendrites were finer and less tapered. Cells in which we could identify an outer plexiform tree failed to cover the retina completely, but were nonrandomly distributed. We draw three main conclusions: (1) some nonmammalian vertebrates have separate inner and outer mosaics of large ganglion cells like those of mammals, (2) the vertical displacement of ganglion cell somata can vary widely within a single mosaic and may thus be functionally irrelevant, and (3) biplexiform ganglion cells exist in fish but differ in morphology from the biplexiform types described in some other vertebrates.

The Origin of the Vertebrate Eye / A origem dos olhos dos vertebrados

The Origin of the Vertebrate Eye (A origem dos olhos dos vertebrados).
Autores: Trevor D. Lamb & Edward N. Pugh Jr. & Shaun P. Collin

Artigo que fala sobre A Origem dos Olhos dos Vertebrados.

Para baixar clique aqui.
Download, click here.

The Retinal Wholemount Technique: A Window to Understanding the Brain and Behaviour (A Técnica de Montagem Completa da Retina: uma janela para o entendimento do cérebro e comportamento).

The Retinal Wholemount Technique: A Window to Understanding the Brain and Behaviour (A Técnica de Montagem Completa da Retina: uma janela para o entendimento do cérebro e comportamento).

Autores: Jeremy F.P. Ullmann,  Bret A., Moore, Shelby E. Temple, Esteban Fernández-Juricic & Shaun P. Collin.

Artigo com um protocolo para dissecação e montagem plana de retinas. Para baixar clique aqui: 

Article with a protocol for dissection and flat mount retinas. To download, click here.
 
Artículo con un protocolo para la disección y retinas planos de montaje. Para descargar, haga clic aquí.

Artikel mit einem Protokoll für die Präparation und Flachmontage Netzhaut. Zum Download klicken Sie hier.

Perkara dengan protokol untuk pembedahan dan retina gunung rata. Untuk memuat turun, klik sini.

Abstract

 The accessibility of the vertebrate retina has provided the opportunity to assess various parameters of the visual abilities of a range of species. This thin but complex extension of the brain achieves a large proportion of the necessary visual processing of an optical image before information is delivered to the brain as neural impulses. Studies of the retina as a wholemount or a flattened sheet of neural tissue are abundant due to the large amount of information that can be analysed, as follows: the level of summation or convergence; the coverage, stratification and potential sites of synaptic connections; the spatial resolving power; the arrangement of neuronal arrays or mosaics; electrophysiological access for the recording of responses to visual stimuli; the spatial arrangement of cell dendritic fields; location of retinal ‘blind spots’ (optic nerve, falciform process and pecten); topographic differences in retinal cell sampling; spectral filters, and reflective structures. The present study examines all aspects of the wholemount technique, including enucleation, fixation, retinal extraction, flattening, staining, visualization of labelled cells and stereological mapping of cell density. Uniquely, it highlights the crucial technical and often species-specific differences encountered when examining a range of vertebrate taxa (fishes, reptiles, birds and mammals). This broad comparative approach will enable future studies to overcome technical difficulties, thus permitting larger conceptual questions to be posed regarding the diversity of visual tasks across phylogenetic boundaries.

              Diversity of eye types. / Progressive bleaching of a retina.