Background

Exposure to arsenic has been reported to affect the nervous system in a number of ways. Various epidemiological studies suggest cognitive impairment in subjects following exposure to environmental arsenic. The goal of the present study was to determine if supplementation of exogenous α-lipoic acid (ALA) could ameliorate sodium arsenite (NaAsO₂) induced adverse effects on learning and memory and synaptic connectivity in rat hippocampus.

Methods

Accordingly, NaAsO₂ alone (1.5/2.0 mg/kg bw) or NaAsO₂ along with ALA (70 mg/kg bw) was administered by intraperitoneal (i.p.) route from postnatal day (PND) 4–17 to Wistar rat pups (experimental groups) and the Control groups received either distilled water or no treatment at all. After carrying out Elevated Plus Maze (EPM) and Morris Water Maze (MWM) test, the fresh brain tissues were collected on PND 18 and processed for Golgi Cox staining.

Results

Observations of MWM test revealed impaired learning and memory in iAs alone treated animals as against those co-exposed to iAs and ALA. In Golgi stained hippocampal sections of iAs alone treated animals, decreased dendritic arborization and reduced number of spines in pyramidal neurons (CA1) and granule cells (DG) was observed whereas neuronal morphology was preserved in the controls and ALA supplemented groups

Conclusions

These observations are suggestive of beneficial effects of ALA on iAs induced effects on learning and memory as well as on hippocampal neuronal morphology.

中文翻译：

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α-硫辛酸对砷酸钠暴露大鼠海马神经元的空间记忆和结构完整性的影响。

背景

据报道，接触砷会以多种方式影响神经系统。各种流行病学研究表明，暴露于环境砷后受试者的认知障碍。本研究的目的是确定补充外源性α-硫辛酸（ALA）是否可以缓解亚砷酸钠（NaAsO ₂）诱导的对大鼠海马学习记忆和突触连接性的不利影响。

方法

因此，从出生后（PND）4-17天开始，通过腹膜内（ip）途径向Wistar大鼠幼崽施用单独的NaAsO ₂（1.5 / 2.0 mg / kg bw）或NaAsO ₂连同ALA（70 mg / kg bw）。组）和对照组接受蒸馏水或完全不接受治疗。进行高架迷宫（EPM）和莫里斯水迷宫（MWM）测试后，将新鲜的脑组织收集到PND 18上并进行高尔基·考克斯（Golgi Cox）染色。

结果

MWM测试的观察表明，与单独暴露于iA和ALA的动物相比，单独用iA处理的动物的学习和记忆受损。在单独接受iAs治疗的动物的高尔基染色海马切片中，观察到锥体神经元（CA1）和颗粒细胞（DG）的树突状乔化减少和刺数减少，而对照组和ALA补充组的神经元形态得以保留

结论

这些观察结果暗示ALA对iA诱导的对学习和记忆以及对海马神经元形态的影响的有益作用。