Lamellar bodies in the synaptic cytoplasm of the accessory cone from the chick retina as revealed by electron microscopy

Abstract

Lamellar bodies observed in the presynaptic cytoplasm of the accessory cone from the chick retina fixed with glutaraldehyde by vascular perfusion were studied by electron microscopy. Ball-shaped lamellar bodies were measured that are approximately 0.7 μ in diameter; they consist of numerous paired membranes that appear like stack or a concentric circle, either compact or loosely arranged. The lamellar bodies are in close interrelation with surrounding cell organelles, namely, synaptic vesicles, endoplasmic reticula, dense tubular network, and neurofilaments. The composition of the lamellar bodies is still unknown, but after saliva digestion their internal structure completely disappears. Their possible histogenesis is discussed. Moreover, additional observations of the synaptic ribbon are presented.