Application Of Microdialysis Technique In Rat Central Fatigue Model

In modern life, people fall across all kinds of opportunities and challenges. In the face of more stress and competition, many of them produce the imbalance of excitability and inhibition of central nervous system, consequently show symptoms such as daze, low emotion, insomnia and weariness, influence personal life quality badly. So, researchers have paid more and more attention to fatigue. However, the mechanism of fatigue is unknown well now yet, which handicaps the treatment of the disease. Therefore, it is necessary to build a model for effectively and quantitatively assessing fatigue level.According to Traditional Chinese Medicine theory, a sleep deprivation fatigue model was built with flower-pot technique. Using microdialysis technique, brain extracellular fluid in freely moving rats was sampled, and using HPLC, the levels of amino acid neurotransmitters of samples were analyzed. The dialysis performances of self-made microdialysis probe was tested, and was found that the probe had good recovery and stability. Thus, it was applied to the central fatigue model. 4h acute and 120h chronic microdialysis experiments (including 2h baseline, 72h sleep deprivation and 48h sleep recovery) were made to discuss the dynamic changes of amino acids (such as Glu, GABA, Tau) and Glu/GABA in brain extracellular fluid during sleep deprivation and sleep recovery.The results demonstrate that sleep deprivation is a process from excitement to inhibition. During early stage of SD, the levels of Glu, GABA and the ratio of Glu/GABA all increase, rat behaves excitedly;during late stage of SD, the levels of GABA and Tau increase significantly, while the ratio of Glu/GABA decrease significantly, rat behaves inhibitorily, CNS produces inhibitory protection, videlicet produces central fatigue;during sleep recovery, the levels of GABA and Tau begin decrease, the ratio of Glu/GABA begin increase, indicating fatigue is recoverable. In the second recovery day, the levels of amino acids have no significant differencescomparing to CC group.Membranous milkvetch root injection (MMRJ), a Chinese Traditional medicine, was applied to central fatigue model. It shows MMRI rat is less excited than SD rat during early stage of SD, showing higher quietness;while more excited than the one during late stage of SD, CNS remains relative excitability. The results indicate that MMRI have some effect of anti-fatigue.This paper establishes the neuroscience index for evaluating central fatigue quantificationally, which is good to the research of mechanism of central fatigue and efficiency and exploiture of anti-fatigue Traditional Chinese medicine.