Abstract: Forty-seven female Sprague-Dawley rats received stereotaxic injections of 6-OHDA (8 μg/4μl) containing 0.02% ascorbic acid into the right medial substantia nigra of ventral tegmen mesencephalon. Twenty-three successful models were obtained by injections of 0.5 mg/kg apomorphine at 2, 4, 6, 8 weeks after operation respectively. The rats, choosed from successful models, were poured and fixed, then floating slices, frozen slices and vibration slices of the brain were made separately 2 weeks, 1 month and 2 months after operation. The specimen were examined by ABC and revealed that the Tyrosine hydroxylase (TH) positive cells were decreased to about 15% in surviving 2 weeks rats. About 98% TH positive cells of compact substantia nigra were disappeared in surviving 1 month and 2 months rats. Right substantia nigra cells were found to be reduced to 5% with massive proliferation of glias by TH and nissl double technique, while the left substantia nigra areas were remain normal. This study confirms that dopaminergic and noradrenaline neurons were selectively destroyed by 6-OHDA.

Key words: 6-hydroxy dopamine (6-OHDA), Apomorphine, Tyrosine hydroxylase, Substantia nigra