The afferent nerve fibers were excited possibly belong to the different functional groups.Excitation of each group of fibers will cause algesia or analgesia respectively.

• 电子麻醉和电活力测试仪刺激所兴奋的神经纤维可能属于不同的功能亚群，它们的兴奋分别产生镇痛作用和疼痛。