Rat Models Of Vascular Dementia, Hippocampal Neuron Map-2, Nf Expression

Objective To investigate the expression of MAP-2 and NF inCA1 region of hippocampus, and its relation to spatial learning and memory function in the late stage of global ischemic-reperfusion injury in rats.Methods Sixty Wistar rats with normal learning and memory tested by Morris Water Maze before ischemic-reperfusion injury were used in this study. The rats were divided into four groups by random: 1Normal control group (n=6); 2Vertebral artery Occlusion control group (VO); 3Bilateral Common Carotid Artery Occlusion 20min Reperfusion control group (BCCO/R); 4Global Ischemia 20min Reperfusiongroup (GI/R). According to animal surviving period, the later three groups were subdivided into 3 groups, day 7, 14 and 30. There were 6 rats each group. These rats were tested in Morris Water Maze before sacrified. The expression of MAP-2 and NF were detected by immunohistochemistry (ABC methods) and the intensity of immunostaining was measured using MedHPIAS pathologic imaging-analysis system. Coronal slices with Nissl's staining were used to count neurons in Hippocampus CA1 regions.Result Compared to groups, normal, VO and BCCO/R, the rats in GI/R group adopted an inefficient search strategy, and escape latency became . longer following elongation of reperfusion (P<0.01). In Hippocampus CA1 regions the number of neurons was not reduced in groups Normal,VO and BCCO/R, but decreased in GI/R groups (P<0.01), and the number of neurons also had significant differences among the GI/R 7d, 14d and 30d groups (P<0.01). Compared to normal group, the expressions of MAP-2 and NF in Hippocampal CA1 region obviously reduced in BCCO/R7d group (P<0.05), but in groups BCCO/R 14d and 30d their expressions had no significant change (P>0.05). In groups GI/R the neurite with immunostaining of MAP-2 and NF were not observed, but strong staining of these two proteins was present in perikaryon of the neurons, compared to Normal, VO and BCCO/R groups (P<0.05).Conclusion Rat with global ischemia and reperfusion had animpairment of spatial learning and memory, reflecting that this model can be used for the research of vascular dementia. The expression pattern of MAP-2 and NF indicated neuronal plasticity responding to injury. The finding that MAP-2 and NF were aggregated in cytoplasm might imply their protective roles to neuron, eg. Survival, in vascular dementia.