de Medeiros Magda Alves, Canteras Newton Sabino, Suchecki Deborah, Mello Luiz Eugênio A M
Department of Physiological Sciences, Universidade Federal Rural do Rio de Janeiro, BR 465 Km 7, 23851 970 Seropedica, RJ, Brazil.
Brain Res. 2003 May 30;973(2):196-204. doi: 10.1016/s0006-8993(03)02479-x.
The need to use anaesthetised or restrained animals in acupuncture research in laboratory animals may represent a confounding variable, since both anaesthesia and stress alter the pain threshold and the activity of pain-related brain areas. In the current study we assessed the participation of the periaqueductal gray (PAG) in electroacupuncture's (EA) analgesic effects applied to the Zusanli point (36S) under carefully controlled stress conditions. Repeated immobilisation protocols (6 days, 1 h/day and 13 days, 2 h/day) were used to diminish the influence of acute immobilisation stress on c-Fos expression and analgesia (tail-flick test) induced by electroacupuncture on the 36S point (EA36S). Animals submitted to immobilisation alone (IMMO) or to electroacupuncture (100 Hz, 2-4 V, faradic wave) on a non-point region (EANP) were compared with animals submitted to electroacupuncture on the 36S point. In animals not previously submitted to repeated immobilisation, electroacupuncture on the 36S point induced analgesia and c-Fos expression in the PAG was not different from that induced by electroacupuncture at a non-acupuncture point. In animals submitted to repeated immobilisation (repeated immobilisation for 6 days or repeated immobilisation for 13 days), however, electroacupuncture on point 36S led to higher levels of analgesia and c-Fos expression, specifically in the ventrolateral PAG (vlPAG), as compared with animal groups subjected only to immobilisation or to electroacupuncture on a non-point. Our findings endorse previous results, and point to a specific part of the PAG involved in the effects of electroacupuncture at the Zusanli point.
在实验动物的针灸研究中使用麻醉或受限动物可能代表一个混杂变量，因为麻醉和应激都会改变痛阈以及与疼痛相关脑区的活动。在本研究中，我们在精心控制的应激条件下，评估了中脑导水管周围灰质（PAG）在电针刺激足三里穴（36S）产生的镇痛效应中的作用。采用重复固定方案（6天，每天1小时和13天，每天2小时）来减少急性固定应激对电针刺激36S穴（EA36S）诱导的c-Fos表达和镇痛（甩尾试验）的影响。将仅接受固定（IMMO）或在非穴位区域接受电针刺激（100Hz，2 - 4V，感应电）（EANP）的动物与接受36S穴电针刺激的动物进行比较。在未预先接受重复固定的动物中，36S穴电针刺激诱导的镇痛以及PAG中的c-Fos表达与非穴位电针刺激诱导的情况没有差异。然而，在接受重复固定（重复固定6天或重复固定13天）的动物中，与仅接受固定或非穴位电针刺激的动物组相比，36S穴电针刺激导致更高水平的镇痛和c-Fos表达，特别是在腹外侧PAG（vlPAG）中。我们的研究结果证实了先前的结果，并指出了PAG中参与足三里穴电针效应的特定部分。
