1. Conclusions Substantial nigral pathology of PD rats makes the foundation of the rotational behaviour.

2. The results indicate that suspension grafts of embryonic nigral tissue can ameliorate behavioural impairments induced by dopamine-depleting 6-OHDA lesions.

3. Conclusion:1. The grafted nigral cells can reconstruct the nervous function though integrating into host brain.

4. Results The number of substantia nigral apoptosis cells was increased and positively related to the changes of doses and durations of use of levodopa.

5. Aim:To explore the influence of paraquat on cerebral mitochondrial respiratory chain activity and the possible mechanism of paraquat to damage nigral neurons.

6. Conclusions The study showed that apoptosis was a main death mode of nigral neuronal cells in 6 OHDA induced PD model rats, which may play a key role in the development of Parkinson's disease.

7. Conclusion Estrogen plays an important role in protecting the substantia nigral dopaminergic neuron of female rats.

8. Immunohistochemical analysis demonstrated colocalization of APLP2 and tyrosine hydroxylase in the nigral neurons.

9. Furthermore, endogenous toxin formation in the brain leads to a variety of processes that initiate nigral cell death in Parkinson's disease.