The immediate early gene c fos is rapidly and transiently expressed in neurons in response to stimulation. The aim of the present study is to observe the effec ts of acupuncture on c fos expression of periaqueductal gray(PAG)

nucleus raph e magnus (NRM)and dorsal raphe nucleus(DRN) in carrageenan inflammation rats.Rats were divided into control

carrageenan inflammation and acupuncture groups. Except control group

each rat was received a unilateral injection of carrageen an (Sigma

2 mg/100 μL per paw) into the hind paw. The results showed that the nociceptive threshold of control and inflammation rats were 13.34±2.11 sec and 1.74±0.22 sec indicating that the hyperalgesia was induced by carrageena n. The number of the labeled Fos LI neurons in PAG

NRM and DRN was significant ly increased (18.90±1.79 to 44.25±2.91

P<0.001

2.57±0.84 to 9.60 ±1.88

P<0.05 and 15.33±1.59 to 31.39±3.55

P<0.001

respe ctively). Electroacupuncture (EA) unilateral "Zusanli"(ST 36) and "Kunlun"(BL 60) acupoints(2 and 60 Hz alternately

1～ 3 mA

30 min) significantly elevated the nociceptive threshold of the carrageena n injected paws(P<0.05). At the same time

in the EA treated rats the number of labeled Fos LI neurons was significantly decreased in PAG and DRN (44 .25±2.91 to 17.86±1.63

P<0.01

31.39±3.55 to 18.27±2.02

P< 0.05)

but not in NRM(9.60±1.88 to 8.83±2.21

P>0.05). The re sults indicate that the EA supressed the carrageenan inflammation induced Fos ex pression in PAG and DRN

but not in NRM in rats.