Objective To observe the effect of electroacupuncture(EA)intervention at different treatment time-points on locomotor function and neuronal apoptosis in rats with acute spinal cord injury(ASCI)

so as to explore its mechanism underlying improvement of ASCI.Methods Seventy-two female Wistar rats were randomly divided into sham operation

ASCI model and EA groups which were further divided into 4time-points:1

3

7and 14d(n=6at each).The ASCI model was established by weight-drop striking the exposed spinal cord(T10)using a NYU impactor device.EA(0.4-0.6mA

100Hz)was applied to bilateral"Jiaji"(EX-B 2)for 30 min

once a day for 1

3

7and 14 days

respectively in the EA group.The Basso-BeattieBresnahan(BBB)grading score was used to assess the animals' locomotor function

and H.E.staining was used to display the pathological changes of spinal cord injury at different time points.The TUNEL staining was used to detect the nerve cell apoptosis of spinal cord tissue.Results After ASCI

the BBB scores were significantly decreased and the numbers of the apoptotic nerve cells considerably increased on day 1

3

7and 14 in the model group compared with the sham operation group(P<0.05).In addition

H.E.staining showed severe damage of the spinal cord tissue

infiltration of inflammatory cells

increase of dead nerve neurons and glia cells in the number from day 3to 7

and additional increase of vacuoles on day 14.Following EA intervention

the decrease of BBB scores and the increase of apoptotic nerve cell numbers were markedly suppressed on day 3

7and 14(P<0.05).The TUNEL staining showed a decrease of the apoptotic nerve cells from day 3on and an improvement of the injuredtissue structure from day 7to 14 in the EA group.Conclusion EA stimulation of EX-B 2can significantly improve locomotor function

and lighten the spinal cord injury in ASCI rats

presenting a time-dependant tendency

which may be associated with its effect in reducing neuronal apoptosis in the spinal cord.