Tang F R, Tan C K, Ling E A
Department of Anatomy, Faculty of Medicine, National University of Singapore.
J Hirnforsch. 1995;36(3):411-20.
Comparative ultrastructural study of the sympathetic preganglionic neurons that innervated the superior cervical ganglion (SPN-scg) was made between spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto rats. After injection of choleragen subunit-B horseradish peroxidase (CB-HRP) into the superior cervical ganglion, three types of the sympathetic preganglionic neurons were identified according to their ultrastructural features. In both SHR and WKY rats, the neurons in the autonomic region of T1-T3 segments of the spinal cord showed a characteristic distribution pattern in which the Type I neurons were located more laterally in n. intermediolateralis pars funicularistic (ILf), and n. intermediolateralis pars principalis (ILp), Type III neurons more medially in n. intercalatus spinalis (IC), n. intercalatus pars paraependymalis (ICpe) and Type II neurons in n. intermediolateralis pars principalis (Ilp) as well as in n. intercalatus spinalis (IC). Of the three types of neurons, there was not noticeable ultrastructural difference in Type II and Type III neurons between the SHR and WKY rats. Some differences, however, were observed in Type I neurons between the two animals stains. In SHR, the nucleus of Type I neurons displayed many deep indentations and a greater number of profiles of Golgi apparatus. Three types of the axon terminal were found to make synaptic contacts with the labelled Type I neurons. Some proportional changes of the different axon terminals were observed between those of SHR and WKY rats. The results of this study suggest that the suppressive effect on the activity of the sympathetic preganglionic neurons in SHR may be attenuated which would result in an unbalanced activities of some of neurotransmitters on the sympathetic preganglionic neurons thereby leading to the onset of hypertension. The increase in the number of nuclear indentations and an increased activity in the Golgi complex may reflect an increase in the synthesis of some of the neurotransmitters or neuromodulators in the sympathetic preganglionic neurons or their axon terminals. The characteristic distribution patterns of the three types of neurons suggest that, of the three types of SPN-scg, only the Type I neurons may be implicated in the regulation of the cardiovascular system.
对支配颈上神经节的交感神经节前神经元（SPN - scg）进行了超微结构比较研究，实验对象为自发性高血压大鼠（SHR）和年龄匹配的正常血压Wistar - Kyoto大鼠（WKY）。向颈上神经节注射霍乱毒素B亚基辣根过氧化物酶（CB - HRP）后，根据超微结构特征鉴定出三种类型的交感神经节前神经元。在SHR和WKY大鼠中，脊髓T1 - T3节段自主区域的神经元呈现出特征性的分布模式，其中I型神经元位于中间外侧索部（ILf）和中间外侧主部（ILp）更外侧，III型神经元位于脊髓中间插入核（IC）、室管膜旁中间插入核部（ICpe）更内侧，II型神经元位于中间外侧主部（Ilp）以及脊髓中间插入核（IC）。在这三种类型的神经元中，SHR和WKY大鼠的II型和III型神经元在超微结构上没有明显差异。然而，在两种动物的I型神经元染色中观察到了一些差异。在SHR中，I型神经元的细胞核显示出许多深陷痕以及大量高尔基体轮廓。发现三种类型的轴突终末与标记的I型神经元形成突触联系。在SHR和WKY大鼠的轴突终末之间观察到了不同轴突终末的一些比例变化。本研究结果表明，对SHR交感神经节前神经元活动的抑制作用可能减弱，这将导致一些神经递质对交感神经节前神经元的活动失衡，从而导致高血压的发生。核凹陷数量的增加和高尔基体复合体活性的增加可能反映了交感神经节前神经元或其轴突终末中一些神经递质或神经调节剂合成的增加。三种类型神经元的特征性分布模式表明，在三种类型的SPN - scg中，只有I型神经元可能参与心血管系统的调节。
