Efficacy of needling Baihui (GV20), Neiguan (PC6), Shenmen (HT7) and Taichong (LR3) on cerebral cortical blood oxygen level in rats with insomnia.

Objective: To evaluate the effect of needling Baihui (GV20), Neiguan (PC6), Shenmen (HT7) and Taichong (LR3) on cerebral cortical blood oxygen level in rats with insomnia identified as liver- stagnation pattern in terms of Traditional Chinese Medicine.

Methods: Sixty Wistar rats were randomly divided into blank group ( 10), the rest of the rats were clamped tail as stimulation combined with injected intraperitoneally p-chlorophenylalanine (PCPA) to establish sleep deprivation model. After the successful replication of the model, they were randomly divided into model group, grabbing group, Western Medicine group, acupuncture group and sham acupuncture group, with 10 rats in each group. The model group was given normal saline; The grasping group was grasped in the same way as the two treatment groups; Western medicine group was given estazolam solution; The acupuncture group was treated with the acupuncture method of "soothing the liver and regulating mind" needling Baihui (GV20), Neiguan (PC6), Shenmen (HT7) and Taichong (LR3); The sham acupuncture group were needled with four non-acupoint sites. After 7 d of treatment of rats in each group, sodium pentobarbital sleep experiment was used to evaluate the sleep latency (SL) and sleep time (ST). The percentage of rats entering the open arm (OE%) and the percentage of time entering the open arm (OT%) in each group were monitored by elevated cross maze, and the vertical score, horizontal crossing times, central grid score and modification times were monitored by open field test, functional near infrared spectroscopy (fNIRs) was used to monitor the changes of oxygenated hemoglobin (Oxy-Hb), deoxyhemoglobin (Deoxy-Hb) and total hemoglobin (Total-Hb) in the cerebral cortex of rats in each group under light stimulation and dark stimulation, the statistically significant channel combinations were selected from 8 light sources and 12 detectors (S-D). According to the position of the light source detector covering the cerebral cortex, Preliminarily determine the key brain areas of insomnia (the preliminary experiment found that 6S-8D and 7S-9D were the key channels of insomnia under light stimulation, and the corresponding brain areas were prefrontal lobe and occipital lobe respectively; 7S-7D channel under dark stimulation, and the corresponding brain area was occipital lobe); The hemodynamic map of cerebral cortex was constructed through the absolute value of whole brain blood oxygen level. Further identify key brain regions for insomnia.

Results: Compared with the blank group, ST, OE%, OT%, the vertical score, horizontal crossing times, central grid score, the concentration of Deoxy-Hb in prefrontal and occipital lobes were decreased significantly (<0.01), and the concentrations of SL, modification times, Oxy-Hb and Total-Hb were increased significantly (<0.01); There was no difference in the above indexes between the model group and the grabbing group (>0.05); After treatment, ST, OE%, OT%, the vertical score, horizontal crossing times, central grid score and Deoxy-Hb concentration in acupuncture group and Western medicine group increased significantly, while SL, modification times, Oxy-Hb and Total-Hb concentrations were decreased significantly (<0.01, <0.05), Compared with the Western Medicine group, the values of OE% and OT% were more significantly higher in the acupuncture group (<0.05), while the rest of the indexes were not significantly different between the two groups (>0.05); Compared with the acupuncture group, ST, OE%, OT%, the vertical score, horizontal crossing times, central grid score and the concentration of deoxy Hb in the sham acupuncture group decreased significantly (<0.01), and the concentrations of SL, modification times, Oxy-Hb and Total-Hb increased significantly (<0.01).

Conclusions: The needling method for soothing the liver and regulating mind could improve the abnormal behavior of insomnia rats with liver stagnation, and its effect on the improvement of abnormal mood caused by insomnia with liver stagnation is better than that of Western Medicine, and the mechanism of action may be related to the regulation of blood oxygen metabolism in the prefrontal and occipital lobes of the cerebral cortex by acupuncture.