Objective: To study the influence of Longmu Guizhi decoction(LD) on the α2A-AR mRNA expression in the left and right brain of juvenile spontaneously hypertensive rat(SHR)

a rat model of attention deficit hyperactivity disorder(ADHD)

and to investigate the mechanisms of LD for ADHD. Method: Male SHRs were randomly divided into high-dose LD group(18 g·kg-1)

low-dose LD group(9 g·kg-1)

methylphenidate group(3.75 mg·kg-1)and model group(saline

10 mL·kg-1). All the SHRs were lavaged for 14 days. The α2A-AR mRNA expression in the left and right prefrontal cortex

corpus striatum were detected by the method of Real-time PCR. Result: In the right prefrontal cortex

α2A-AR mRNA expression was significantly decreased in the methylphenidate group and two LD groups compared with model group(P<0.05)

but there was no obvious change in the left prefrontal cortex in all the groups. In the right corpus striatum

compared with saline control group

α2A-AR mRNA expression was significantly decreased in the methylphenidate control group

but it was significantly increased in the two LD groups. In the left corpus striatum

α2A-AR mRNA expression was significantly increased in the methylphenidate control group(P<0.05)

there was no obvious change in other groups. Conclusion: The produce of ADHD may have a certain correlation with α2A-AR.The potential mechanism of LD in the treatment of ADHD is related to that it can decrease α2A-AR mRNA expression in the right prefrontal cortex

and increase its expression in the rigtht corpus striatum.