Our ability to see is facilitated by a light-sensitive tissue layer. The so-called retina detects visual information about our surroundings. Its specialised cells are here shown in a sidelong slice (retina front shown bottom of the image). Among the cells coloured magenta are the rods and cones – photoreceptor cells – that sense light and turn it into transmissible impulses. Ganglion cells (the majority of the cells dyed green) carry these impulses along nerve fibres to the brain for interpretation. Researchers can identify these cell types by highlighting their unique proteins. This study of MAP(RA4) protein in chick retina reveals that some of these green-dyed cells are not, as first assumed, always ganglion cells but include other retinal cells at different stages of development. Understanding the development and cellular composition of the eye provides a firm basis for the study of defects that can cause blindness.
Written by Jenny Gimpel
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