可阻滞性是循经感传的一个重要特征

对于探讨循经感传的形成机理有重要的意义

但产生这一现象的原因尚不清楚。目前

存在着“中枢干扰”和“外周阻断”两种不同的看法。为了弄清这个问题

我们决定依次从大脑皮层

脊髓和外周三个水平加以分析探讨。1984年

我们已经报道In this work we further obsesved the influence of mechanical pressuse and tactile stimulation on the activities of the first order of relay nuclei of somatosensory system.The former had no obvious influence on the spinal somatosensosy evoked potential(SSEP)

but the latter decreased its amplitude markedly.Furthermore

there was a significant positive correlation between the changes of CSEP and SSEP under the influence of tactile stimulation (r=0.856

P<0.01).Judging by the results obtained it is clear that during acupuncture the somatic afferent activities was primarily interfered by tactile stimulation in the spinal cord

and the changes of the functional activities of SI was secondry.Having clarify this point

we can further infer the exact site where PSC was blocked by mechanical pressure.In view of the fact that mechanical pressure had no obvious influence on the somatic afferent activities either in SI or spinal cord

we have to explore the answer of the question from the site outside CNS in next step.In other words

PSC may probably be blocked at the“periphery”.However

the final conclusion can be made only after the direl evidences have been obtained.