Methamphetamine ( METH ) , a powerful stimulant of amphetamine type in the central nervous system ( CNS ) , is a new kind of synthetic drugs mainly in psychological dependence. Long-time abuse will lead to strong neurotoxicity and drug de-pendence. Recently it has become the abuse problem in public health. Autophagy is a process of degradation and utilization of the cellular components by the lysosome, which widely exists in eukaryotic cells. Many studies show that methamphetamine can iduce autophagy,but the underlying mechanism is not fully un-derstood yet . Therefore,the mechanisms and signaling pathways of autophagy by methamphetamine and the roles of autophagy in methamphetamine induce neurotoxicity are reviewed in this pa-per, so as to provide reference materials for further research of methamphetamine and autophagy.

The methamphetamine(METH)addiction is a compensatory adaptation of the central nervous system after the long-term exposure to METH in the molecular,cellular,neuronal loop function and brain structure.As a new type of post transcriptional regulatory molecules and regulatory factors,miRNAs are a large number of regulatory factors in the central nervous system.Studies have shown that miRNAs play an important role in the regulation of METH addiction.This paper is to review and summarize the expression features and the regulatory role of miRNAs in METH addiction,as well as the different expression of miRNAs in different tissues and organs.The aim of this paper is to provide a reference for further study on the role of miRNAs molecules in METH addiction and the discovery of new drug targets.

Objective To introduce a single person operation procedure for tail vein injection in conscious tree shrews,and to improve the success rate of injection. Methods The tree shrew was fixed by a canvas glove and a clamp. The tail of the tree shrew was fixed by the operator's left hand, and the drug was injected by the right hand with a 1 mL disposable syringe. Results This method had the advantages of simple operation,economy and practicality,good fixation effect,high matching degree of animals and high success rate of drug administration. Conclusions Compared with other methods,this method has obvious advantages such as single person operation, convenient, time-saving and labor-saving. The cost is low and the effect is good,thus significantly improving the success rate of injection.

OBJECTIVE：To stu dy the mechanism of improvement effects of Gastrodin injection on methamphetamine induced neurotoxic damage in rats via nNOS pathway. METHODS ：SD rats were randomly divided into control group ，methamphetamine group，regular-dose of gastrodin group ，double-dose of gastrodin group ，negative control （NC）adenovirus group ，NC adenovirus+ methamphetamine group ，NC adenovirus+gastrodin group and nNOS adenovirus+gastrodin group ，with 10 rats in each group. Control group was given normal saline intraperitoneally ，twice a day. Methamphetamine group was given methamphetamine intraperitoneally（7.5 mg/kg），twice a day. Regular-dose and double-dose of gastrodin groups were respectively given different doses of Gastrodin injection （10，20 mg/kg）intraperitoneally 30 min earlier ，once a day ，and then given methamphetamine intraperitoneally by the same way as methamphetamine group. NC adenovirus group was given NC adenovirus （4.8×107 PFU）3 μL once in the striatum and normal saline intraperitoneally ，twice a day. NC adenovirus+methamphetamine group was given NC adenovirus by the same way and methamphetamine （7.5 mg/kg）intraperitoneally，twice a day. NC adenovirus+gastrodin group was given NC adenovirus+methamphetamine by the same way ，meanwhile given Gastrodin injection intraperitoneally （20 mg/kg）30 min before methamphetamine ，once a day. nNOS adenovirus+gastrodin group was given nNOS adenovirus and methamphetamine by the same way ，meanwhile given Gastrodin injection intraperitoneally （20 mg/kg）30 min before methamphetamine ，once a day. Each group was given relevant medicine intraperitoneally 1 mL/100 g，for consecutive 3 days. The stereotyped behavior of rats were observed and scored ；the apoptotic rate ，the protein expression of apoptotic factors （Bcl-2，Bax，Cleaved caspase- 3），the levels of oxidative stress factors （MDA，SOD，GPx） and NO ，the protein expression of nNOS were detected. RESULTS ： Compared with control group ，stereotyped behavior score ，cell apoptosis rate of striatum ，protein expression of Bax ，Cleaved caspase-3 and nNOS ，the levels of MDA and NO were increased significantly in methamphetamine group ；while the protein expression of Bcl- 2 and the levels of SOD and GPx were decreased significantly （P＜0.05 or P＜0.01）. Compared with methamphetamine group ，stereotyped behavior score ，cell apoptosis rate of striatum ，protein expression of Bax ，Cleaved caspase- 3 and nNOS ，the levels of MDA and NO were decreased significantly in regular-dose and double-dose of gastrodin groups ；while the protein expression of Bcl- 2，the levels of SOD and GPx were increased significantly ，and most above indexes in double-dose of gastradin group were better than regular-dose of gastrodin group （P＜0.05 or P＜0.01）. Compared with NC adenovirus group ，cell apoptosis rate of striatum ，protein expression of Bax ，Cleaved caspase- 3 and nNOS ，the levels of MDA and NO were increased significantly in NC adenovirus+methamphetamine group ；while the protein expression of Bcl- 2，the levels of SOD and GPx were decreased significantly （P＜0.01）. Compared with NC adenovirus+methamphetamine group ，cell apoptosis rate of striatum ，protein expression of Bax ，Cleaved caspase- 3 and nNOS ，the levels of MDA and NO were decreased significantly in NC adenovirus+ gastrodin group ；while the protein expression of Bcl- 2，the levels of SOD and GPx were increased significantly （P＜0.01）. Compared with NC adenovirus+gastrodin group ，cell apoptosis rate of striatum ，protein expression of Bax ，Cleaved caspase- 3 and nNOS，the levels of MDA and NO were increased significantly in nNOS adenovirus+gastrodin group ；while the protein expression of Bcl- 2，the levels of SOD and GPx were decreased significantly （P＜0.01）. CONCLUSIONS ：Gastrodin injection can protect rats against neurotoxic damage induced by methamphetamine ，and the effect is related to the inhibition of nNOS-mediated apoptosis and oxidative stress.