Parkinson's disease (PD) is a well-known neurodegenerative disorder associated with a high risk in middle-aged and elderly individuals, severely impacting the patient's quality of life. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is frequently used to establish PD in animals. Dendritic spines are dendritic processes that form the foundation of learning and memory. Reportedly, dendritic spine density of striatal medium spiny neurons (MSNs) declines in PD, and this decline has been associated with PD progression; however, the underlying mechanism remains elusive. Herein, we used the MPTP animal model to examine whether serum-induced kinase (SNK) and spineassociated Rap guanosine triphosphatase (SPAR) contribute to decreased dendritic spine density in striatal MSNs. MPTP was used to establish the animal model, which exhibits motor function impairment and dopaminergic cell loss. To assess spine density, Golgi staining was performed to count striatal dendritic spines, which were reduced in the MPTP group when compared with those in the normal control group. Immunohistochemistry was performed to analyze changes in SNK and SPAR expression. MPTP treatment significantly increased the expression of SNK in striatal MSNs, whereas that of SPAR was significantly decreased when compared with the normal control group. These findings offer clues to further explore the mechanism of declining dendritic spine density in patients with PD and provide evidence for potential target identification in PD.
The Heihe Water Diversion Project in Zhouzhi County, Shaanxi Province is a "lifeline" engineering project that supplies water as well as electric power to Xi'an City, China. This canyon-type reservoir is located at the mouth of the Heihe River on the northern flank of the Qinling Mountain. Slope stability of the reservoir bank is one of the critical geological engineering problems, among which the toppling rock slope of Shuimengou is a major threat to the dam and downstream residents. The toppling rock mass was formed by downcutting of the river, and the hard thin-layer metamorphic schist gradually bended under the action of gravity. Monitoring data in recent decade showed that the process of toppling continued slowly. Under the erosion of the reservoir water the stability of the toppling slope may deteriorate in the coming time. Hence, it is essential to predict the stability of the slope and to give a proposal for mitigation. For this purpose, this paper simulates and analyzes the deforming process of the toppling slope in geological history using the discontinuous deformation analysis (DDA) method. Furthermore, in consideration of the reservoir erosion at the foot of the slope the future deformation-failure of the slope is also simulated. Based on the result, a reasonable counter measure is proposed for stabilizing the slope.
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