Effects of electroacupuncture stimulations of two different intensities (pulse amplitude 3V

6V)and frequencies(10Hz

200Hz)on levels of 5-HT

HIAA

NA and DA were compared in 6 rat brain regions (oblongata plus pons

hypothalamus

hippocampus

striatum

midbrain and cortex). 1.5-HT levels in the oblongata plus pons and cortex were increased by electroacupuncture stimulation of 6V

but were not increased by 3V. The frequency of 10Hz was no obvious difference as compared with 200Hz in the effects on brain 5-HT concentrations. 2.5-HIAA concentrations in the striatum and cortex were increased only using electroacupuncture stimulations of combination of higher intens- ity (6V) and lower frequency (10Hz). 3. NA level in the striatum was decreased by frepuency of 200 Hz

but was not decreased by 10 Hz

the effect of 3V on striatum NA level was no significant different as compared with 6V.Responses of NA concen- tration in the cortex to electroacupuncture stimulations of different intensi- ties and frequencies seemd to be different as compared with that in the stri- atum 4. Both frequency and intensity parameters of electroacupuncture were involved in the increases of DA levels in brain

but proper combinations of differet pulse amplitudes with different frequencies were necessary for the DA increases in brain. In addition

the response of DA level in the oblon- gata plus pons to different electroacupuncture parameters also were differ- ent from that in the hypothalamus. The results partially explain contradictions of the results obtained by laboratories using various electroacupuncture parameters in studies on rela- tionships between acupuncture and monoamine neurotransmitters. Therefore

the studies on the parameters would be very important for deep-going rese- arch of acupuncture mechanism and raising acupuncture clinical efficiency.