stimulation threshold
1.It was observed that when the stimulation intensity reached the threshold of C fiber,the NRM neurons were obviously activated,and when it reached or exceeded theintensity for producing the maximal C wave,the NRM neurons were highly acti-vated.
2.(2) In 7 out 8 tests, the pain threshold in ipsi-lateral corresponding receptive field was changed by alone stimulation of posterior limb representation of SⅡ, but not in SⅠ. During simultaneous stimulation of SⅠ and SⅡ the pain threshold in ipsila:eral receptive field was also elevated obviously.
3.Seizure of rats was kindled by electric stimulation,the To determinate and compare the after discharge threshold(ADT) and current intensity that stage 5 seizure thresh old(ST) needed were determined and compared between the two groups.
4.Pain threshold to mechanical stimulation with von Frey filament was measured before (baseline) and 2, 6,12, 48, 96 h after operation.
5.Mechanical and thermal pain threshold were measured by paw withdrawal latencies to von Frey hair and radiant heat stimulation at 1 d before operation (baseline) and 1, 3, 5, 7 d after operation.
6.The stimulation consisted of a 500 mstrain of monophasic,rectangular-wave pulses(1 ms,40 Hz),and the current incre-ment was 0.1 mA per step delivered every five seconds. The minimal electric cur-rent required to produce defensive response of head and forelimbs was taken asvisceral pain threshold.
7.Results AESC could elevate threshold for localized seizure by direct cortical stimulation in rats. AESC (348 mg/kg,ig) produced an effect 1 h,peaked 2～3 h after administration; and lasted 10 days;
8.Withdrawal threshold to von Frey filament stimulation intensity and response latency of the hindpaw to radiant thermal in control group were significantly lower than those in Sham group( P <0.01). Cumulative pain score in control group was significantly higher than that in Sham group( P <0.01).
9.Results: It could obriourly increase the sex ogaro weight of castrated mice and rats, raise the pain threshold value of heat stimulation, inhitite the mouse auricle tumefaction degree induced by xylol, reduced Evans blue excretion of mouse peritonitis induced by acetic acid.
10.Results In experimental group the pain threshold to mechanical stimuli (von Frey hair stimulation) and cold stimuli (acetone test) on the operated side were significantly decreased after L4 spinal nerve transection as compared to the baseline values before operation and significantly lower than in sham operation and control groups.
