Learning and memory ability in improved models of synthetic vascular dementia / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE Toexplorethecredibityoftwoimprovedmodelsofsyntheticvascular dementia(VD)rats.METHODS OneimprovedmodelofVDratswasestablishedbyligatuingthebilat-eral common carotid artery twice at 3 d (improved 2-VO),while the other was established by blocking the middle cerebral artery on the left side by separating pterygopalatine arteria (i mproved MCAO/R). The learning and me mory ability was determined by escape latency in Morris water maze directional navi-gation test and cross-over ti mes in target areas in spatial probe test and the search strategy.The organi-zational structure in CA1 area of the hippocampus was observed and analyzed under a microscope after HEstaining.RESULTS Thelearningandmemoryabilitydecreasedsignificantlyin2modelgroupsat 20 d after the operation.The escape latency was much longer in improved 2-VO group and improved MCAO/R group than that in sham group(P<0.05)especially in improved 2-VO group.41 d after the operation,no difference between MCAO/R and sham group (P <0.05 ).The differences between improved 2-VO group and sham group remained significant(P<0.01 ),and difference between improved 2-VO group and improved MCAO/R group was significant(P<0.01 )at 41 d.The cross-over times in the target area in spatial probe test decreased more significantly in 2 model groups than in sham group. 41 d after the operation,improved MCAO/R group was not different from sham group(P<0.05). Search strategy results showed that swimming trajectory in the improved 2-VO groupwas mostly edge and random type,but was of tendency type and straight type in the improved MCAO/R group.In the organization structure of hippopal CA1 area of rats,the nu mber of cells was reduced,their arrange ment was sparse and chaotic,the morphology of cells was inco mplete,the structure of cells was abnormal, cytoplasmwasscarce,andnucleoliwereinconspicuous.CONCLUSION TwoimprovedVDmodelscan lead to behavior and pathological changes in rats.The i mproved 2-VO model,si mple and stable,is suitable for drug efficacy research.The improved MCAO/R model is the ideal short-term efficacy study.