关键词: 平滑肌细胞, 化学突触, 缝隙连接, 并置膜结构, 中华宽体金线蛭, AP神经元

Abstract: Anterior pagoda (AP) neurons of leeches were marked by intracellular injection of horseradish peroxidase (HRP). The intercellular connection were observed under transmission electron microscope between the smooth muscle cells in outer capsule and inner capsule of the neural ganglion, and between the marked axonal terminals of AP neuron and smooth muscle cells. Usually, single smooth muscle cell spread over the outer and inner capsules of ganglia in the shape of spindle-and elliptical-like respectively. There are two kinds of filaments:thin and thick filaments and dense patches in the smooth muscle cells. The membrane of smooth muscle cells grew out protrusions. Many glycogen granules, mitochondria and rough endoplasmic reticulum can be seen in the cytoplasm of smooth muscle cells. The distance between embedded smooth muscle cells in outer capsule ranges from 13.1 to 26.1 nm. This paper is the first report on the synapses formed between axonal processes and smooth muscle cells in the outer capsule of leech ganglion, for the chemical synapse the intercellular cleft is measured in 10.2 to 15.3nm; as for the width of intercellular gap between the marked AP axonal terminal and smooth muscle cell of the outer capsule ranges from 2 to 2.5nm that corresponded to the width of gap junction.

Key words: smooth muscle cell, chemical synapse, gap junction, Whitmania pigra, AP neuron, opposite membrane structure