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Objectives: To compare the effects of electroacupuncture (EA) with different time intervals on corticospinal excitability of the primary motor cortex (M1) and the upper limb motor function in healthy subjects and observe the after-effect rule of acupuncture., Methods: Self-comparison before and after intervention design was adopted. Fifteen healthy subjects were included and all of them received three stages of trial observation, namely EA 0 group (received one session of EA), EA 6h group (received two sessions of EA within 1 day, with an interval of 6 h) and EA 48h group (received two sessions of EA within 3 days, with an interval of 48 h). The washout period among stages was 1 week. In each group, the needles were inserted perpendicularly at Hegu (LI 4) on the left side, 23 mm in depth and at a non-acupoint, 0.5 cm nearby to the left side of Hegu (LI 4), separately. Han 's acupoint nerve stimulator (HANS-200A) was attached to these two needles, with continuous wave and the frequency of 2 Hz. The stimulation intensity was exerted higher than the exercise threshold (local muscle twitching was visible, and pain was tolerable by healthy subjects, 1-2 mA ). The needles were retained for 30 min. Using the single pulse mode of transcranial magnetic stimulation (TMS) technique, before the first session of EA (T0) and at the moment (T1), in 2 h (T2) and 24 h (T3) after the end of the last session of EA, on the left first dorsal interosseous muscle, the amplitude, latency (LAT), resting motor threshold (rMT) of motor evoked potentials (MEPs) and the completion time of grooved pegboard test (GPT) were detected. Besides, in the EA 6h group, TMS was adopted to detect the excitability of M1 (amplitude, LAT and rMT of MEPs) before the last session of EA (T0*)., Results: The amplitude of MEPs at T1 and T2 in the EA 0 group, at T0* in the EA 6h group and at T1, T2 and T3 in the EA 48h group was higher when compared with the value at T0 in each group separately ( P <0.001). At T1, the amplitude of MEPs in the EA 0 group and the EA 48h group was higher than that in the EA 6h group ( P <0.001, P <0.01); at T2, it was higher in the EA 0 group when compared with that in the EA 6h group ( P <0.01); at T3, the amplitude in the EA 0 group and the EA 6h group was lower than that of the EA 48h group ( P <0.001). The LAT at T1 was shorter than that at T0 in the three groups ( P <0.05), and the changes were not obvious at the rest time points compared with that at T0 ( P > 0.05). The GPT completion time of healthy subjects in the EA 0 group and the EA 48h group at T1, T2 and T3 was reduced in comparison with that at T0 ( P <0.001). The completion time at T3 was shorter than that at T0 in the EA 6h group ( P <0.05); at T2, it was reduced in the EA 48h group when compared with that of the EA 6h group ( P <0.05). There were no significant differences in rMT among the three groups and within each group ( P >0.05)., Conclusions: Under physiological conditions, EA has obvious after-effect on corticospinal excitability and upper limb motor function. The short-term interval protocol (6 h) blocks the after-effect of EA to a certain extent, while the long-term interval protocol (48 h) prolongs the after-effect of EA.

Objective: To compare the effect of electroacupuncture (EA), motor training (MT) and EA combined with MT on motor learning and motor cortex excitability in healthy subjects, and to explore the effect of EA combined with MT on synaptic metaplasticity., Methods: Using self-control design, 12 healthy subjects were assigned into an EA group, a motor training group (MT group) and an EA plus motor training group (EA+MT group) successively, wash-out period of at least 2 weeks was required between each group. EA was applied at left Hegu (LI 4) in the EA group for 30 min, with continuous wave, 2 Hz in frequency and 0.5-1 mA in density. Motor training of left hand was adopted in the MT group for 30 min. EA and motor training were adopted in the EA+MT group successively. The time of finishing grooved pegboard test (GPT) was observed, and the average amplitude of motor evoked potentials (MEPs), the rest motor threshold (rMT) and the latency were recorded by transcranial magnetic stimulation technique before intervention (T0), after intervention (T1) and 30 min after EA (T3) in the EA group and the EA+MT group, T0 and T1 in the MT group., Results: Compared with T0, the time of finishing GPT was shortened at T1 in the MT group and at T2 in the EA group and the EA+MT group ( P <0.01, P <0.05), the average amplitude of MEPs was increased at T1 in the 3 groups and at T2 in the EA group and the EA+MT group ( P <0.05, P <0.01). Compared with T1, the time of finishing GPT at T2 was shortened in the EA group and the EA+MT group ( P <0.05, P <0.01), the average amplitude of MEPs at T2 was increased in the EA group ( P <0.05). The time of finishing GPT at T2 in the EA+MT group was shorter than the EA group ( P <0.05). There were no statistical differences in rMT and latency at each time point among the 3 groups ( P >0.05)., Conclusion: In physiological state, electroacupuncture combined with motor training have a synergistic effect on motor learning, while have no such effect on excitability of cerebral motor cortex.

Objective: To explore the excitatory effect of the sensory cortex through somatic electroacupuncture (EA) stimulation at Taichong (LR3)., Methods: Ten healthy volunteer men ranging in age from 20 to 50 years were enrolled in this study. EA (2 Hz, a tolerable strength) was applied to the left LR3. Before and after EA, the somatosensory evoked potential (SEP) from the Cz' area of the scalp was recorded by electrical stimulation of the bilateral dorsal penile nerves and the indentation behind the medial malleolus of the foot, termed as the pudendal SEP (PSEP) and lower extremity SEP (LSEP), respectively., Results: The amplitude of the left LSEP induced by stimulation of the left medial malleolus was significantly increased after EA (P < 0.05), but there were no significant changes in the latency of LSEP and PSEP, and the amplitude of right LSEP evoked by stimulation of the left medial malleolus, and that of the PSEP., Conclusion: EA at LR3 increases the excitability of the contralateral cerebral sensory cortex (lower extremity area), but has no effect on the adjacent sensory cortex (genital area).

Objective: To observe the plasticity between hand and face representations of the motor cortex of healthy volunteers after electroacupuncture(EA) at Hegu(LI4), so as to provide a scientific basis for the theory of "Hegu is indicated for orofacial problems"., Methods: Using a cross-over design (self-controlled study), 10 healthy volunteers were randomly assigned to an acupuncture group and a sham acupuncture group (two-weeks wash-out period between the two groups). Subjects in the acupuncture group received EA stimulation (2 Hz, 0.5 to 1 mA, 30 min) at LI4 on their left hands. Adhesive pads sticked on the left hands of subject in the sham acupuncture group, thus, the placebo needle provided participants with a similar appearance to that in the acupuncture group but no skin penetration, and the placebo needles were connected to an EA device with a broken wire inside. Using transcranial magnetic stimulation technology, the motor evoked potentials (MEPs) of the first dorsal interosseous muscle and the orbicularis oculi muscle in hand and face representations in the contralateral motor cortex were recorded before and after EA and sham EA, and the total amplitude, effective stimulation area and center of gravity of MEPs were calculated., Results: Compared with that before intervention, for acupuncture group, the total amplitude of MEPs in hand representation in the contrala-teral motor cortex was significantly increased( P <0.05),while the total amplitude of MEPs in face representation was significantly decreased ( P <0.05). The effective stimulation area in hand representation was significantly increased( P <0.01), and there was no difference in face representation( P >0.05). The difference in the center of gravity of the X-axis in hand representation was statistically significant ( P <0.05)，with the center of gravity moved an average of 0.6 cm to the outside, and there was no difference in face representation ( P >0.05). There was no difference in the center of gravity of the Y-axis in hand and face representations( P >0.05). For sham acupuncture group, there were no differences in total amplitude of MEPs, effective stimulation area and the center of gravity in hand and face representations ( P >0.05)., Conclusion: EA at LI4 can induce plasticity between the hand and face representations of the motor cortex in healthy volunteers (exciting the hand representation of the motor cortex, while inhibiting the motor cortex representation), which provides a scientific basis for treating facial and mouth diseases by acupuncture at LI4 and the theory of selecting acupoints of the corresponding meridian distal to the disease location.

Previous studies have shown that there are many common structures between the neural network of pain and memory, and the main structure in the pain network is also part of the memory network. Chronic pain is characterized by recurrent attacks and is associated with persistent ectopic impulse, which causes changes in synaptic structure and function based on nerve activity. These changes may induce long-term potentiation of synaptic transmission, and ultimately lead to changes in the central nervous system to produce "pain memory". Acupuncture is an effective method in treating chronic pain. It has been proven that acupuncture can affect the spinal cord dorsal horn, hippocampus, cingulate gyrus and other related areas. The possible mechanisms of action include opioid-induced analgesia, activation of glial cells, and the expression of brain derived neurotrophic factor (BDNF). In this study, we systematically review the brain structures, stage of "pain memory" and the mechanisms of acupuncture on synaptic plasticity in chronic pain.

Objective: To investigate the constituents of Ervatamia hainanensis systematically., Method: Various chromatographic techniques were applied to isolate and purify the constituents of this plant. The structures were elucidated by spectroscopic analysis., Result: Eight compounds were obtained, which were identified as alpha-amyrin acetate (1), 11-oxo-alpha-amyrin acetate (2), beta-sitosterol (3), cycloart-23-ene-3beta, 25-diol(4), cycloart-25-ene-3beta, 24-diol (5), 5alpha, 8alpha-epidioxyergosta-6, 22-dien-3beta-ol (6), ibogamin-3-one (7), beta-daucosterol (8)., Conclusion: Compounds 1, 2, 4- 7 were isolated from this plant for the first time.