Abstract: 【Objective】 The purposes of this study are to make up a deficiency of ultrastructures of neurons and varicosis in intestinal nerve of Remak (INR) of chicken, and to provide a rational foundation for future physiologic function researches of INR.【Method】 Neurons and varicosis in INR of chicken were observed with transmission electron microscope. 【Result】 Considerable number of large neurons and a little small intensely fluorescent cells were found in INR. Neurons were enclosed by scattered satellite cells, which didn’t form integrity envelopes. Sinapsic contacts between neurons and satellite cells were also found. Because of lack normal basal lamina, the cell membrane of neurons directly contacted with intercellular substance. The shape of nucleus in neurons was round, and the nucleus had smooth surface. Loosen and clear chromatins, rhoptries and nucleoli with integrity structure were found in nucleus of neurons. While, in cytoplasm, many special organelles distributed in it. These organelles included the copious microtubules, active Golgi apparatuses, active rough endoplasmic reticulum which often contained inflated endoplasmic reticulum cisterna, fenestrated dense granules which could be neuropeptide, plenty of free ribosomes, mitochondria with diversified shapes and some of which were pyknosis to some extent. A little clumped small intensely fluorescent cells with high electron density cytoplasm and nucleus distributed under capsule of INR, which can form asymmetry synapses each other. According to the different kinds of synaptic vesicle they contained, 4 kinds of varicosis were found in the INR, which formed different function synaptes with surrounding structures. 【Conclusion】 The ultrastructural characteristics of INR neurons suggested that the INR posses actively synthesis and secretion function, 4 kinds of varicosis and their different synaptic connections indicated the diversity and comlexity of INR functions.

Key words: chicken, intestinal nerve of Remak, neurons, varicosis, ultrastructure