Objective To observe the therapeutic effect of electroacupuncture(EA)at five Back-Shu points on sleep

hippocampal peripheral benzodiazepine receptor(PBR) expression and hypothalamic 5-hydroxytryptamine(5-HT)

5-hydroxyindoleacetic acid(5-HIAA)

tumor necrosis factor alpha(TNF-α)and interleukin(IL)-1β contents in insomnia rats

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

model

EA and medication(Diazepam)groups(n=10 rats in each group). The insomnia model was established by intraperitoneal injection(i. p.)of para-Chlorophenylalanine(PCPA

300 mg/kg)once daily for2 days. EA(60 Hz

1 mA)was applied to bilateral five Back-Shu points

i. e.

Feishu(BL13)

Xinshu(BL15)

Ganshu(BL18)

Pishu(BL20)and Shenshu(BL23)for 10 min

once daily for 6 days. Rats of the medication group were treated by gavage of Diazepam(0. 92 mg/kg)once daily for 6 days. The sleep duration was recorded after i. p. of Pentobarbital Sodium(45 mg/kg). Histopathological changes of the hippocampus were displayed by H. E. staining. The contents of 5-HT

5-HIAA

TNF-α and IL-1β in the hypothalamus were assessed by using ELISA. The expression levels of PBR mRNA and protein in the hippocampus were detected by quantitative real-time PCR

immunohistochemistry and Western blot

separately.Results Following modeling

the sleep duration was considerably shortened in rats of the model group relevant to the control group(P<0. 05). After the treatment

the sleep duration was significantly increased in both EA and medication groups relevant to the model group(P<0. 05). After modeling

the hippocampal neurons were obviously decreased in number

and disordered in the arrangement

the levels of hypothalamic 5-HT

5-HIAA

TNF-α

and IL-1β were significantly down-regulated(P<0. 05)

and the expression of PBR mRNA and protein in hippocampus was obviously increased relevant to the control group(P<0. 05). Following the treatment

the hippocampal neurons were increased in number and arranged regularly

and the contents of hypothalamic 5-HT

5-HIAA

TNF-α

and IL-1β were considerably increased(P<0. 05)

and the expression of PBR mRNA and protein in hippocampus was significantly decreased in both EA and medication groups relevant to the model group(P<0. 05). The therapeutic effect of EA was comparable to that of medication in increasing sleep duration

body weight

5-HT and 5-HIAA contents(P>0. 05)

and significantly superior to that of the medication in increasing TNF-α and IL-1β levels(P<0. 05)

and considerably superior to that of medication in down-regulating PBR mRNA and protein expression(P<0. 05).Conclusion EA at five Back-Shu-points of the five Zang-organs can significantly improve the sleep in insomnia rats

which is closely associated with its effects in reducing the expression of PBR in hippocampus and up-regulating the levels of 5-HT

5-HIAA

TNF-α and IL-1β in hypothalamus.