Study on the ultrastructural characteristic of segments of photoreceptors from retinas of neonatal calf / 中华眼底病杂志

ABSTRACT

Objective To study on the ultrastructural characteristic of segments of photoreceptors from neonatal retinas for supporting donor retina choice of retinal transplantation. Methods Photoreceptors from neonatal calf and adult calf were analysed by scanning electron microscopy and transmission electron microscopy. Results Segments of photoreceptors from neonatal calf appeared the mushroom pattern, in which, distal end of outer segment which was ball shaped formed the head with mushrooms appea rance, and the inner segments along with some of outer segments formed the body with mushrooms appea rance. Within the outer segment, plasma membranes of adjacent evaginations form a disk subsequently. The array of most disks were vertical to the entire length of segments, but some were parallel and slope to. Owing to the incomplete formation, some rim of disk near distal end of outer segment revealed step shaped appearance. The distal end of outer segment displays some processes consisted of membranous discs, much vesicular material and mitochondria, much rough endoplasmic reticulum (RER) and numerous polysomes. Segments of photoreceptor connected with outer nuclear layer via the external limiting membrane. Conclusion The typical morphological structures of outer segments suggest the immature and strong gowth ability of photoreceptors of the retina of neonatal calf, and therefore the competence for donor material of retinal transplantation.