Research On Changes Of VTA-NAc In Heroin Addicted Rats

Objective: The model of heroin addiction and abstention treatment wasestablished and the symptoms of abstention of rats were observed. The study onthe changes of ultrastructure and expression of TUNEL in the ventral tagmentalarea(VTA) and nucleus accumbens(NAc) was done to explore the lesions in thebrain caused by heroin. Method: Rats were randomly divided into three groups:control group, model group and treated group. The animal model was made byprogressively increase of heroin dosage. And then Methadone---Buprenorphine---Clonidine were used to treated group. The VTA---NAc fromthree groups were examined by TUNEL and observed under eletronic microscope.Result: Significant symptoms of abstention in model group appeared. In TUNELreaction, the number of apoptotic neurons of the model and the treated group washigher than that in the control group(P<0.01). Degeneration, apoptosis and oncosiswere also found in the neuronal somas, axons and dendrites in the model andtreated groups. But the pathological changes in model group were more serverecompared with treated group. TUNEL reaction and ultrastructural image in theVTA---NAc of control group were normal. Conclusion: Heroin-addiction canresult in serious impairment of CNS. Degeneration is a main form of pathologyand apoptosis is a main form of neuron death. Anti-apoptosis therapy may be anew way to treat heroin addiction.