Neuronal Degeneration Induced Physical Stress

为了研究生理压力对大鼠脑的影响，在成年雌性和雄性大鼠身上进行了四项实验。这些书的题目如下：1.游泳训练对大鼠海马神经元退化的影响，2。大鼠海马左右半球与运动诱导神经变性的关系，2。游泳耐力训练6周后大鼠学习记忆能力的变化；耐力游泳后大鼠海马CA3亚区细胞内Ca^<2+>的能量色散x线分析。实验结果表明，耐力游泳等运动应激可引起严重的神经损伤和功能退化。在6-12周游泳训练2-3小时的大鼠海马的背下、CA3亚区和齿状回中发现大量的深色神经元。经过12周的训练，CA3和耻骨下的细胞密度明显降低。深色染色的神经元与先前报道的缺血性和/或低血糖性神经变性极为相似。游泳训练12周后，大鼠大脑杏仁核、顶叶皮质1区和梨状皮质均出现了强烈的神经元退化。在海马体中，游泳训练引起的退化神经元经常出现在右半球而不是左半球。此外，能量色散x射线分析证实，游泳2小时增加了CA3锥体神经元细胞外Ca^<2+>浓度。在空间认知测试中，上述运动性神经变性大鼠的学习能力低于正常大鼠。

To study the effects of physical stress on the rat brain, four experiments were took-place in adults female and male rats. The title of them were as follows ; 1.Degeneration of rat hippocampal neurons in response to swim training, 2.Difference between left and right hemispheres of rat hippocampus in relation to exercise-induced neuro-degeneration, 3.Leaming and memory abilities of rats subjected to endurance swim training for 6 weeks, and 4. Energy dispersive X-ray analysis of Intracellular Ca^<2+> in the rat hippocampal CA3 subfield after endurance swim.These experiments revealed that the exercise stress such as endurance swimming induced the serious neuronal damages and functional deterioration. In detail, Numerous dark neurons histochemically stained were found in the subiculum, CA3 subfield and dentate gyrus of rat hippoampus subjected to 2-3 h swim training for 6-12 weeks. The cell density was significantly decreased in the CA3 and subiculum after 12-week training. The profiles of darkly stained neurons were extremely similar to the ischemic and/or hypoglycemic neuro-degenerations previously reported. Also, the intensely degenerated neurons were observed in the amygdaroid, parietal cortex area 1, and piriform cortex of rat brain after 12-week swim training. In the hipocampus, the degenerated neurons induced by swim training were frequently found in the right rather than in the left hemisphere. Furthermore, Energy dispersive X-ray analysis confirmed that a bout of 2-h swimming increased the extracellular Ca^<2+> concentration of CA3 pyramidal neurons. Subjected to a spatial cognitive test, the learning ability of rats with exercise induced neuro-degeneration mentioned above was inferior to that of normal ones.