|
ObjectiveThe vascular dementia rat model behavior to explore the possible pathogenesis of VD observation and analysis features and pathology, provide certain theoretical basis for the early intervention.MethodsBy Morris water maze training method screening cognitive similar level of rats were included in the experiment, using D-galactose stimulus preparation of aging rats, and randomly divided into control group, sham operation group, operation group2weeks,4weeks of operation group and operation group6weeks. Operation2weeks group,4weeks group and6weeks group using a modified four vessel occlusion (4-VO) method to establish the VD animal model, using Morris water maze test, VD model of rats after2weeks,4weeks,6weeks on the average escape latency of learning and memory, and the blank control group and sham operation group difference. All rats in the Morris water maze test were divided from the day after, whole brain and hippocampus, brain for the preparation of pathological section, HE staining, observe the morphological changes of hippocampus neurons and the density of white matter regions under light microscope; hippocampus for tissue homogenate, determination of cholinergic transmitter Ach content to ELISA Kit.Determination of neural cholinergic receptor expression of nAchR a4, a7mRNA to RT-PC1Comparison of a behavioralBy Morris water maze training for1weeks and group the rats, before modeling the escape latency between groups had no significant difference (P>0.05); model, sham operation group and control group rat escape latent period and there was no significant difference (P>0.05), operation group and the escape latency of rats than in the control group and sham operation group prolonged significantly (P<0.05); a comparison between the operation and the2,4,6weeks, there was also a significant difference (P<0.05), as with the postoperative time prolonged, the escape latency prolonged.2hippocampus neuronal morphologyAfter HE staining, nerve cells can be clearly observed under the light microscope, the cytoplasm was pink, with blue-black nucleus. The control group and the CA1area of hippocampus neurons in rats of sham operation group arranged in neat rows, close, complete structure, abundant cytoplasm, nucleus of the neurons and glial cells without exception. Neurons in hippocampal CA1region of the model group VD arranged in disorder, scattered, neuron structure is destroyed, the volume decreases, nuclear degeneration, karyopyknosis into triangular or irregular shape,After sixth weeks in rats is most obvious.3cerebral white matter morphologyAfter HE staining, light microscope control white matter cells group and sham operation group rats were ordered, dense, no loose; VD model group, the white matter axonal density decreased significantly, there were vacuolar pathology; and with the modeling time, pathological change tends to be serious, in postoperative sixth the most obvious rats.4Determination of the content of AchCompared with the control group, sham operation group, the content of Ach had no significant change (P>0.05), while the VD model2,4,6weeks in rats of Achgroup were significantly, The expression of nAch a4, a7mRNA:compared with the control group, sham operation group, nAchR a4, a7expression of mRNA had no significant change (P>0.05), while the VD model2,4,6weeks group rat nAchR a4, a7mRNA expression were significantly reduced (P<0.05)Conclusion1The method to prepare VD rat models by D-galactose stimulus aging combined with4-VO method embolization of the vertebral artery has high feasibility with low mortality and high success rate.2.Reduced hippocampal CA1neurons is the pathological basis of learning, memory ability of rats to learn3.Leukoaraiosis is VD another main pathology foundation.4.Hippocampal cholinergic neurotransmitter content of Ach reduced, and neurogenic cholinergic receptor nAch a4, a7mRNA expression, leading to cholinergic pathway was inhibited, as the molecular basis of VD.
|