THE PROLIFERATION AND DIFFERENTIATION OF NEURAL PROGENITORS IN THE SN OF PARKINSONIAN RATS / 解剖学报

ABSTRACT

Objective To observe the proliferation and differentiation of the neural progenitors in the midbrain substantia nigra(SN) of adult rat when dopaminergic neurons(DA neurons) were destroyed. Methods The Parkinson disease model(PD model) was induced in adult SD rats by steriotaxic injection of 6-OHDA into the right striatum,and then assessed by behavioral analysis to screen the qualified models.After varied survival period,the brain of model rats were perfused and fixed by 4% paraformaldehyde,moved the segment of SN,embedded with paraffin and coronally sectioned continuously.The microsections were processed by immunohistochemistry labeling separately the neural progenitors with anti-nestin monoclonal antibody,the dividing cells with anti-PCNA(proliferation cell nuclear antigen),the neuronal precursors with anti-Tuj1(?-tubulin isotype Ⅲ),and DA neurons with anti-TH(tyrosine hydroxylase).The labeled cells were counted under microscope and analyzed statistically.(Results It) was found in the right SN of PD model rats that 1.Nestin positive(Nestin~+) cells appeared 10d after 6-OHDA injection,became abundant on 14d,declined in number on 17d,and disappeared on 21d.2.Weakly positive PCNA(PCNA~+) cells appeared on 7d.PCNA~+ cells were abundant on 14d,decreased in number from 21d,with only a few positive cells noticed on 28d.3.Tuj1 positive cells appeared in small number on 10d,became abundant on 14d,decreased in number from 17d and dropped nearly to zero on 21d.4.The number of TH positive neurons was significantly less than the normal control(by 24%) on 7d,and became even less as time elapsed.Conclusion When 6-OHDA is injected into the striatum of adult rats to cause degeneration and death of the DA neurons there,there would be a certain period of time in which a number of neural progenitors will be induced to proliferate actively and differentiate toward neuronal cells(except DA neurons).