Mekhail N A, Nawar N N, Khairallah P A
Division of Anesthesiology, Cleveland Clinic Foundation, Ohio.
Acta Anat (Basel). 1988;133(2):102-6. doi: 10.1159/000146623.
The synapses of the rat superior cervical sympathetic ganglion were studied with both conventional and ultrastructural histochemical methods. Besides the cholinergic synapses polarized from preganglionic fibers to sympathetic ganglion neurons, two morphologically and functionally different types of synapses were observed in relation to the small granule-containing (catecholamine-containing) cells of the rat superior cervical ganglion. The first type is an efferent adrenergic synapse polarized from granule-containing cells to the dendrites of the sympathetic ganglion neurons. This type of synapse might mediate the inhibitory effects (slow inhibitory postsynaptic potentials) induced by catecholamines on the sympathetic neurons. The second type is a reciprocal type of synapse between the granule-containing cells and the cholinergic preganglionic fibers. Through such synapses, these cells could exert a modulating effect on the excitatory preganglionic fibers. Therefore, we propose that these cells, through their multiple synaptic connections, exhibit a local modulatory feedback system in the rat sympathetic ganglia and may serve as interneurons between the preganglionic and postganglionic sympathetic neurons.
采用传统组织化学方法和超微结构组织化学方法对大鼠颈上神经节的突触进行了研究。除了从节前纤维到交感神经节神经元极化的胆碱能突触外，在大鼠颈上神经节含小颗粒（含儿茶酚胺）的细胞方面还观察到两种形态和功能不同的突触类型。第一种类型是从含颗粒细胞到交感神经节神经元树突极化的传出肾上腺素能突触。这种类型的突触可能介导儿茶酚胺对交感神经元诱导的抑制作用（缓慢抑制性突触后电位）。第二种类型是含颗粒细胞与胆碱能节前纤维之间的一种相互性突触。通过这种突触，这些细胞可以对兴奋性节前纤维发挥调节作用。因此，我们提出，这些细胞通过其多个突触连接，在大鼠交感神经节中表现出一种局部调节反馈系统，并且可能作为节前和节后交感神经元之间的中间神经元。
