Abstract:

Objective  To study the behavioral abilities and morphological changes on neurons of substantia nigra of Parkinson′s disease(PD) model rats induced by 6hydroxydopamine(6-OHDA) and observe the effect of the AdTrack-CMV-noggin plasmid on the PD model rats. Methods  Sixty mature Sprague-Dawley male rats were randomly divided into the normal control group, the model group and the noggin treatment group. The PD rat model was established by microinjection of 6-OHDA solution into the right corpus striatum. The AdTrack-CMV-noggin plasmid was injected into the same area after two days in the noggin treatment group, and an identical volume of saline was given to the model group and the normal control group. The behavior of rats was detected by QL-small animal revolved apparatus after seven days. Then, TH, TUNEL-and GFAP-immunopositive neurons in the SN were observed under a light microscope, and quantitative analysis was performed by cell morphometric technique. The ultra-microstructure of the neurons was observed by a transmission electron microscope (TEM).  Results  Rotational behavior of the noggin treatment  rats was significantly improved in comparison with those of the model rats (P<0.05). The quantity of TH-positive cells was increased in the noggin treatment group;however, apoptosis cells were significantly decreased (P<0.05). The quantity  and average optical density of GFAPpositive cells were significantly decreased (P<0.05). TH, TUNEL-and GFAP-immunopositive neurons were mainly in the substantia nigra compacta (SNc). Under TEM, moderate electron-density cytoplasm, regular nuclei, complete perinuclear membrane, evenly distributed chromatin and abundant cell organelles in the SN neurons were shown in the normal group; while shrunken nuclei, irregular perinuclear membrane, decreased heterochromatin, collapsed mitochondria cristae, and distended rough endoplasmic reticulum were shown in the model group. Neurons of the noggin treatment group were improved compared with those of the model group, some of which had distinct structure and abundant cell organelles. Conclusion  6-OHDA induces the impairment of neurogenesis in the PD model rats. Noggin could effectively improve the behavior of the PD model rats and decrease the quantity of apoptosis cells and astrocytes, which might be related to promoting neurogenesis in some parts of the SN.

Key words: Dopamine; Parkinson disease; Substantia nigra; Neurons; Rats; Noggin