ABSTRACT
The aim of this study was to investigate the effect of Yokukansan (YKS) on the impairment of spatial memory and cholinergic involvement in a rat model of early-phase Alzheimer's disease (AD). In this model, rats underwent four-vessel transient cerebral ischemia and then were treated with beta amyloid oligomers injected intracerebroventricularly once daily for 7 days. These animals showed memory impairment in an eight-arm radial maze task without histological evidence of apoptosis but with a decrease in expression of hippocampal dynamin 1, an important factor in synaptic vesicle endocytosis. Oral administration of YKS for 2 weeks significantly increased the number of correct choices and decreased the number of error choices in the eight-arm radial maze task (P < 0.05). Moreover, YKS significantly increased high Kâº-evoked potentiation of acetylcholine (ACh) release (P < 0.05) and significantly increased the expression of dynamin 1 (P < 0.01) in the hippocampus. The ameliorative effect of YKS on spatial memory impairment in our rat model of early-phase AD may be mediated in part by an increase in ACh release and modulation of dynamin 1 expression, leading to improved synaptic function. Future studies will determine whether YKS is similarly useful in the treatment of memory defects in patients diagnosed with early-stage AD.
Subject(s)
Alzheimer Disease/drug therapy , Drugs, Chinese Herbal/therapeutic use , Dynamin I/metabolism , Memory Disorders/drug therapy , Acetylcholine/metabolism , Administration, Oral , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Amyloid beta-Peptides/metabolism , Animals , Disease Models, Animal , Drugs, Chinese Herbal/administration & dosage , Hippocampus/drug effects , Hippocampus/metabolism , Injections, Intraventricular , Ischemic Attack, Transient/drug therapy , Male , Maze Learning/drug effects , Maze Learning/physiology , Memory Disorders/metabolism , Memory Disorders/pathology , Rats , Rats, Wistar , Synaptic Transmission/drug effectsABSTRACT
The gravel drain system aims to avert liquefaction in a sandy soil by quickly dissipating excess pore water pressure. Since construction of gravel drains produces no serious vibration and noise, it is suitable to sites in urban areas and adjacent to existing structures. We have developed a compaction-rod type machine which allows efficient construction of gravel drains with additional benefit of producing the compaction effect of the surrounding soil. To verify this effect, we undertook full scale model and field test, confirming that our gravel drains increase the strength of the surrounding soil, and that a compaction rod with a special cone-shaped configuration is most effective in densifying the surrounding soil.(AU)
