Objective To observe the effect of acupuncture and moxibustion on the conditional position preference(CPP)and prefrontal cortical ultrastructure in heroin re-addicted rats.Methods Thirty-two Wistar rats were randomly divided into normal

model

medication and acu-moxibustion(acu-moxi)groups

with 8 cases in each.Re-addiction model was established by repeated intramuscular injection of heroin into the hindlimbs.Rats of medication group were treated with intragastric administration of Methadone during detoxification.For rats in acu-moxi group

acupuncture needle was inserted into "Baihui"(GV 20)and moxibustion treatment was used to bilateral "Shenshu"(BL 23)for 30 min during detoxification.Rats in normal group were given with intramuscular injection of normal saline during addiction.CPP tests were conducted once daily in a spatial place preference box for 8 days.On the 39th day of the experiment

the rats under anesthesia were killed for sampling the prefrontal cortex(PFC)tissue on an ice plate

then

the ultrastructure of the neurons was observed by using a transmission electron microscope.Results After modeling

the rats' staying duration in the dark-box was shortened obviously(P<0.01).After the treatment

the staying duration in dark-box in acu-moxi group was significantly longer than that in model and medication groups(P<0.01).Compared with normal control group

electron-microscopic results indicated that in PFC tissues of model and medication groups

vacuoles and edema of cytoplasm at different degrees

enlargement of the rough endoplasmic reticulum(REPR)

vacuoles or disappearance of mitochondria

reduction of ribosome in number

and widening of the nuclear intermembrance interstice were seen.While in acu-moxi group

the number of mitochondria and ribosome increased slightly

the mitochondrial cristae was clear

the number of REPR increased relatively but dilated slightly

and the intermembrance space was basically normal.Conclusion Acu-moxibustion can improve heroin re-addicted rats' conditional position preference and has a protection effect on the cerebral cortical neurons.