The conduction velocities and spinal projections of single renal afferent fibers in the rat.
The conduction velocities and spinal projections of single renal afferent fibers in the rat.
复制标题
大鼠单肾传入纤维的传导速度和脊髓投射。
DOI：
10.1016/0006-8993(87)91598-8
复制
发表时间：
1987
期刊：
影响因子：
2.9
通讯作者：
Schramm,LP
中科院分区：
文献类型：
--
作者：
Knuepfer,MM;Schramm,LP
本研究应用电生理技术观察了大鼠肾传入纤维的传导速度和脊髓投射。在氯醛糖麻醉的大鼠中，我们电刺激切断的、下胸和上腰背根的外周端，记录并平均肾神经的逆行传导动作电位。在284个对刺激同侧背根T9-L1有反应的单轴突中，大多数被刺激T11-T13根激活。刺激对侧背根不能引起逆向反应。传入纤维可分为两组，根据其传导速度进行区分：一组传导缓慢的轴突，可能由无髓鞘（0.3-2 m/s，76%）和薄髓鞘（2-9 m/s，19%）纤维组成，另一组传导更快，小的有髓鞘轴突（12-32 m/s，5%）。慢传导纤维和快传导纤维在背根中的分布没有差异。实验后的神经组织学检查显示，小的有髓轴突的直径适合一些，但不是所有的轴突的传导速度在有髓范围内。这些结果表明，在大鼠自主神经中，逆行刺激可识别出单个的有髓和无髓初级传入轴突。他们提供了第一个在大鼠传入肾神经纤维的电生理学描述，他们验证了这些纤维的主要无髓鞘的性质。
This study was designed to examine the conduction velocities and spinal projections of renal afferent fibers in the rat using electrophysiological techniques. In chloralose-anesthetized rats, we electrically stimulated the peripheral ends of cut, lower thoracic and upper lumbar dorsal roots and recorded and averagedantidromically conductedaction potentials in the renal nerves. Of 284 single axons responding to stimulation of ipsilateral dorsal roots T9-L1, the majority were activated by stimulating roots T11–T13. No antidromic responses could be elicited by stimulating the contralateral dorsal roots. Afferent fibers were divisible into two groups, distinguished by their conduction velocities: a population of slowly conducting axons, presumably composed of both unmyelinated (0.3–2 m/s, 76%) and thinly myelinated (2–9 m/s, 19%) fibers, and a population of more rapidly conducting, small myelinated axons (12–32 m/s, 5%). Slowly and more rapidly conducting fibers were not differentially distributed among dorsal roots. Postexperimental histological examination of nerves revealed small myelinated axons with diameters appropriate for some, but not for all, of the axons with conduction velocities in the myelinated range. These results indicate that single myelinated and unmyelinated primary afferent axons can be identified by antidromic stimulation in autonomic nerves of rat. They provide the first electrophysiological description of afferent renal nerve fibers in the rat, and they verify the predominantly unmyelinated nature of these fibers.