[Effect of electrical stimulation and lesion of N reticularis paragigantocellularis lateralis on acupuncture analgesia in rats].

The present study was aimed to investigate the role of the reticularis paragigantocellularis lateralis (RPGL) in acupuncture analgesia. Tail-flick response to electrical stimulation of the tail skin was taken as index of pain response. The first part of the study consisted of four groups: (1) surgical control, (2) electro-acupuncture, (3) electrical stimulation of RPGL, and (4) stimulation of RPGL simultaneously with electro-acupuncture. The pain threshold in the first group was quite stable during the experiments, but increased significantly after electro-acupuncture and/or brain stimulation (n = 14, P less than 0.01; n = 8, P less than 0.001; n = 14, P less than 0.001). The pain threshold of the fourth group increased much more than the second and the third group (P less than 0.001, P less than 0.01). In the second part of the study, the effect of electro-acupuncture was reduced significantly after electrical lesion of the RPGL unilaterally (n = 12, P less than 0.01). The present work indicates that electrical stimulation of RPGL enhances electro-acupuncture analgesia, whereas the lesion of RPGL reduces it. It is suggested that RPGL plays a role in acupuncture analgesia.