ABSTRACT
Objective To investigate the changes of learning and memory function ,vascular endothelial growth factor (VEGF) and heme oxygenase‐1(HO‐1) expression in cerebral cortex and hippocampus of chronic ischemic vascular dementia rats . Methods Thirty‐six healthy SD rats were divided into the control group ,sham operation group and model group ,12 cases in each group .The chronic ischemic vascular dementia rat model was established by the permanent bilateral carotid artery occlusion The sham operation group received the same treatment to the model group except without bilateral carotid artery occlusion .The learning and memory abilities were tested by the Morris water maze experiment and climbing rope strength experiment at 1 ,4 ,8 ,12 weeks respectively .The expressions of VEGF and HO‐1 in rat cerebral cortex and hippocampus was determined by immunohistochemical SP technique .Results The escape latency time at 8 ,12 weeks in the model group was longer than that in the sham operation group and control group ,and the number of crossing the platform was less than that in the sham operation group and control group ,the differences were statistically significant (P0 .05) .The positive expression of HO‐1 and VEGF protein contents in the control group and sham operation group was less than that in the model group with sta‐tistical difference(P<0 .05) .Conclusion Chronic cerebral hypoperfusion has a permanent damage to the learning and memory abil‐ities in rats ,while has no influence on the motor function .VEGF and HO‐1 may play a protective role in chronic cerebral ischemia .
ABSTRACT
@#Objective To observe the effect of chronic cerebral hypoperfusion on abilities of learning and memory and astrocytes in old rats. Methods 50 Wistar rats were randomly divided into the sham group and model group with 25 animals in each group. All animals were assessed with Morris water maze to test the changes of abilities of learning and memory. The expressions of glial fibrillary acidic protein (GFAP) in the frontal lobe and hippocampus were observed immunohistochemically. Results Compared with the sham group, the scores of Morris water maze decreased in the model group, while the astrocytes marked by GFAP proliferated and enlarged significantly. Conclusion Proliferation and morphological changes of astrocytes are involved in pathological mechanism of chronic cerebral hypoperfusion, which might be associated with the decrease of ability of learning and memory.