Dun N J, Karczmar A G, Wu S Y, Shen E
Department of Anatomy, Medical College of Ohio, Toledo 43699.
Acta Neurobiol Exp (Wars). 1993;53(1):53-63.
The sympathetic nervous system evokes complex effects at multiple target organs in response to external, internal as well as mental stimuli. This output involves an interplay between the actions of a number of transmitters and modulators and at the postsynaptic and presynaptic sites of the autonomic ganglia and the sympathetic preganglionic neurons (SPNs). This review concerns particularly the SPNs of the cat and neonatal rat, studied by means of electrophysiological and immunohistochemical methods. Four types of responses may be elicited, the fast EPSP and IPSP, and their currents, and the slow EPSPs and IPSPs, and their currents. Glutamate and glycine appear to mediate the fast excitatory and inhibitory responses, respectively; peptides and amines seem to be responsible for generating the slow excitatory response, while the slow inhibitory response, found so far only in the cat, appears to be mediated by norepinephrine. Finally, glutamate, enkephalin and GABA, but not glycine attenuate the release of the inhibitory and excitatory transmitters from the nerve terminals abutting on the SPNs. The supraspinal efferent and afferent projections which may release the transmitters and modulators in question are discussed, as well the mechanisms that ensure appropriate programming and moment-to-moment regulation of the autonomic output.
交感神经系统会对外部、内部以及精神刺激做出反应，在多个靶器官引发复杂的效应。这种输出涉及多种递质和调质在自主神经节以及交感神经节前神经元（SPN）的突触后和突触前位点的相互作用。本综述特别关注通过电生理和免疫组织化学方法研究的猫和新生大鼠的SPN。可能会引发四种类型的反应，即快速兴奋性突触后电位（EPSP）和抑制性突触后电位（IPSP）及其电流，以及慢速EPSP和IPSP及其电流。谷氨酸和甘氨酸似乎分别介导快速兴奋性和抑制性反应；肽类和胺类似乎负责产生慢速兴奋性反应，而目前仅在猫中发现的慢速抑制性反应似乎由去甲肾上腺素介导。最后，谷氨酸、脑啡肽和γ-氨基丁酸（GABA），而非甘氨酸，会减弱与SPN相邻的神经末梢释放抑制性和兴奋性递质。文中讨论了可能释放上述递质和调质的脊髓上的传出和传入投射，以及确保自主输出进行适当编程和即时调节的机制。
