Objective To observe the effect of electroacupuncture(EA) at “Fengfu”(GV16) and “Taichong”(LR3) on the expression of tyrosine hydroxylase(TH)

α-synuclein(α-syn) and microglial-related microglial(MG)

Toll-like receptor 4(TLR4)/nuclear factor kappa B(NF-κB) signaling pathway in the substantia nigra(SN) of midbrain in Rotenone-induced Parkinson's disease(PD) rats

so as to explore its mechanisms underlying improvement of PD. Methods SD male rats were randomly divided into normal control

PD model and EA groups(n=12 in each group). The PD model was established by subcutaneous injection of rotenone(1 mg/kg) at the back of neck. EA(2 Hz

1 mA) was applied to bilateral GV16 and LR3

once daily for 2 weeks. The rats' behavior(hair color

reaction capacity

locomotion and gait state)scores(0-10 points) were given and the autonomic movement state(trajectory of autonomous motion

total distance

average speed and duration of motion in 8 min) was detected by using open field tests. The immunoactivity of TH and α-syn in the SN tissue were determined by using immunohistochemistry staining

and the number of Iba-1-labelled microglia(MG) was detected by using immunofluorescence staining. The expression levels of TLR4 and NF-κB P65 proteins in the SN were detected by Western blot

and the contents of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) in the SN were determined by using enzyme-linked immunosorbent assay. Results In comparison with the normal group

the behavioral score

α-syn immunoactivity

number of Iba-1 labelled microglia

expression of TLR4 and NF-κB P65 proteins and the contents of TNF-α and IL-6 in the SN were significantly increased(P<0.01)

whereas the total distance

average speed

duration of motion of the autonomic movement in 8 min

and the TH immunoactivity were remarkably decreased in the model group(P<0.01). After EA intervention

compared with the model group

the increase of the behavioral score

α-syn immunoactivity

number of Iba-1-labelled microglia

expression of TLR4 and NF-κB P65 proteins

the contents of TNF-α and IL-6 in the SN

and the decrease of the total distance

average speed

duration of motion of the autonomic movement in 8 min

and the TH immunoactivity were reversed(P<0.05

P<0.01). Conclusion EA can improve the behavioral manifestations of PD rats

which may be associated with its functions in down-regulating the abnormal accumulation of pathological α-syn

TLR4/NF-κB signaling

inhibiting activities of microglia and in up-regulating the expression of TH in the SN of midbrain.