Effect of Xiaoyaosan Decoction on Learning and Memory Deficit in Rats Induced by Chronic Immobilization Stress

Zhen-Zhi Meng,Jia-Xu Chen,You-Ming Jiang,Han-Ting Zhang

doi:10.1155/2013/297154

Abstract

Xiaoyaosan (XYS) decoction is a famous prescription which can protect nervous system from stress and treat liver stagnation and spleen deficiency syndrome (LSSDS). In this experiment, we observed the effect of XYS decoction on chronic immobilization stress (CIS) induced learning and memory deficit in rats from behaviors and changes of proteins in hippocampus. We used XYS decoction to treat CIS induced learning and memory deficit in rats with rolipram as positive control, used change of body weight and behavioral tests to determine whether the rats have LSSDS and have learning and memory deficit or not. We used Western blotting to determine the content of postsynaptic density protein 95 (PSD-95) and synaptophysin (SYP) in hippocampus. Results showed that XYS could improve the situation of slow weight gain induced by CIS, improve the ability of learning and memory, reverse the symptom of liver stagnation and spleen deficiency syndrome (LSSDS) in rats, and increase the levels of PSD-95 and SYP on the hippocampal nerve synapses. These findings suggested that XYS decoction may be helpful in reversing CIS induced learning and memory deficit by increasing the levels of PSD-95 and SYP on the hippocampal nerve synapses and improving synaptic plasticity.

Highlights

Learning and memory deficit is a very important symptom in central nervous system injury [1, 2]
Rats in the chronic immobilization stress (CIS) + saline group displayed worse recognition index in object recognition test compared with the control group
Rolipram or XYS treatments increased the recognition index compared with the CIS + saline group (Figure 3)

Summary

Introduction

Learning and memory deficit is a very important symptom in central nervous system injury [1, 2]. Hippocampal synaptic plasticity plays a key role in learning and memory [3]. CIS significantly decreases the hippocampal volume by 3%–6.3% [5, 6], attenuates long-term potentiation (LTP) in hippocampal slices [7], and causes hippocampal CA3 apical dendritic retraction which parallels spatial memory impairments in male rats [8]. CIS causes dendritic atrophy of the hippocampal pyramidal neurons and alterations in the levels of neurotransmitters in the hippocampus [9]. CIS can induce spatial learning and memory deficit [11], and result in rats with liver stagnation and spleen deficiency syndrome (LSSDS) in traditional Chinese medicine [12]

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Conclusion