Wang_2002_Di.Yi.Jun.Yi.Da.Xue.Xue.Bao_22_193

OBJECTIVE To observe the pathological changes and changes in acetylcholinesterase (AChE) and reduced nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) levels in the marginal division (MrD) following hypoxia, and explore the relation of hypoxia to damages of learning and memory functions. METHODS: Hypoxia models were established in 40 SD rats by treatment with the mixture of 8% oxygen and 92% nitrogen 5 times daily for 5 consecutive days, and the sham-hypoxia group was constituted by 10 rats receiving normal oxygen supply in the same manner as above. Another 10 untreated rats were used as normal control. The rats completing the hypoxia induction procedures were subjected to Y-maze test before their brain sections, along with those of the rats in the other 2 groups, were prepared for HE staining and immunohistochemical staining. RESULTS: AChE immunohistochemical results of the normal control group revealed numerous AChE-positive fibers and some positive cells in the striatum where the MrD was more lightly stained than the other regions. In the rats with hypoxia, however, the MrD was more intensely stained in comparison with the control, but the stain in other regions of the striatum did not manifest any significant differences between the groups. The MrD of normal rats possessed more NADPH-d-positive cells, all spindle-shaped, than the other regions of the striatum, and hypoxia did not result in morphological changes of the cells but significant reduction of their quantity occurred. CONCLUSION: Hypoxia may cause reduction of the learning and memory functions of rats and gives rise to alterations of AChE and NADPH-d staining patterns in the MrD. The MrD is more vulnerable to hypoxia as evidenced by more obvious changes in AChE and NADPH-d staining in the MrD than in the other regions of the striatum, which may be associated with the impairment of the learning and memory functions by hypoxia.