Evaluation of neurotoxic parameter of neurotransimitter release on learning disorder caused by industrial chemicals

通过电击回避实验和大脑皮质ACh、DOPAC、HVA、5-HIAA的释放，研究甲苯和一氧化碳对学习障碍的神经毒性作用。测定高回避大鼠(THA大鼠)和低回避大鼠(WS大鼠)大脑皮层和纹状体的神经递质，以明确控制学习回避行为的脑区和神经递质的种类。大脑皮层和纹状体ACh的释放以及纹状体的单胺代谢产物与高、低回避大鼠的回避能力有关。大鼠自发活动的改变与甲苯暴露后ACh和单胺类代谢产物的释放有关。甲苯兴奋引起的自发活动增加时，ACh和DOPAC、HVA、5-HIAA的释放增加；甲苯的麻醉作用抑制自发活动时，神经递质的释放减少。杠杆按压避震行为的增加可能是由于甲苯的兴奋作用所致。一氧化碳暴露对小鼠学习行为和神经递质的影响不如甲苯暴露明显。

Usefulness as a parameter to evaluate the neurotoxicity on learning disorder caused by toluene and carbon monoxide were studied by shock avoidance results and release of ACh from cerebral cortex and ACh, DOPAC,HVA,5-HIAA from stiatum.Neurotransmitters in cerebral cortex and striatum were measured on the high avoidance rat strain (THA rat) and the low avoidance rat strain (WS rat) for clarify the areas of brain and the kinds of neurotransmitters to control leaning avoidance behavior. ACh release in cerebral cortex and striatum, and monoamine metabolites in striatum were related to avoidance ability between the high and low avoidance rat strains. Change of spontaneous activities of the rats were related to release of ACh and monoamine metabolites on toluene exposure. Release of ACh and DOPAC,HVA,5-HIAA increased when spontaneous activities rose by the exciting action of toluene, and release of neurotransmitters decreased when spontaneous activities suppressed caused by the anesthetic action of toluene. Increase of lever-pressing on shock avoidance behavior seemed to be caused by the exciting action of toluene. The effects of CO exposure on leaning behavior and neurotransmitters were not so clear as toluene exposure.