Effect of spatial learning and treadmill exercise on memory ability in mice = 공간학습과 트레드밀 운동이 생쥐의 기억능력에 미치는 효과

국문 초록 (Abstract)

본 연구에서는 공간학습과 트레드밀 운동이 생쥐의 기억능력에 미치는 효과를 규명고자 하였다. 본 연구의 실험동물은 C57BL 계열 생쥐 6주령 수컷(32.5 ± 2.5 g) 60마리를 사용하였으며, 실험실 환경에 적응시킨 후 대조군, 학습군, 운동군, 그리고 학습- 운동군으로 각 15마리씩 무작위 배정하였다. 운동군과 학습-운동군은 트레드밀 운동을 실시하였는데, 1일 30분, 6주 동안 7 m/min 5분, 10 m/min 5분, 그리고 13 m/min 20분 중강도 운동을 각각 12회, 6회 실시하였다. 공간학습은 radial 8-arm maze 를 사용하여 절수한 실험동물이 5분 이내에 8개 통로의 물을 모두 찾을 때까지 연속적으로 학습군은 6주간 12회, 학습-운동군 은 6주간 6회 훈련시켰으며, 모든 그룹의 실험 전·후로 기억능력을 측정하기 위하여 radial 8-arm maze 검사와 step-down avoidance task를 실시하였다. 해마부위의 5-bromo-2'-deoxyuridine (BrdU) 양성세포수와 brain-derived neurotrophic factor (BDNF)의 발현량을 조사하기 위하여 각각 면역조직화학법과 역전사 중합효소 연쇄반응 (reverse transcription polymerase chain reaction, RT-PCR)법을 실시하였다. 실험결과, 기억능력 검사에서 예상했던 운동과 학습에 따른 가중효과가 관찰되지 않 았지만, 대조군과 비교하여 학습군과 학습-운동군의 기억능력이 유의하게 증가하였다(p < .05). 또한 해마 부위에서 BrdU 양성 세포수는 대조군과 비교하여 모든 실험군에서 유의하게 증가하였고(p < .05), 특히 운동군에서 가장 큰 증가를 보였다(p < .05). 동일한 부위의 BDNF mRNA도 대조군과 비교하여 모든 실험군에서 유의하게 증가하였으나(p < .05), BrdU 양성 세포수와 BDNF mRNA 발현이 일치하는 경향은 나타나지 않았다. 이러한 연구결과는 공간학습과 규칙적인 운동이 BDNF mRNA와 같 은 뇌의 신경영양성 인자를 증가시키고, 새로운 신경세포생성을 촉진시킴으로써 기억능력을 향상시킬 수 있는 가능성이 있음을 보여준다. 다만, 기억능력검사와 신경세포의 증식, 그리고 BDNF mRNA간 정량적 경향성이 일치하지 않는 것으로 보아 신경세포 증식에 작용하는 다양한 신경영양성 인자의 발현을 함께 고려해야 할 것으로 생각된다.

목차 (Table of Contents)

• ABSTRACT
• Introduction
• Materials and Methods
• 1. Animals and treatments
• 2. Spatial learning
• 3. Treadmill exercise protocol
• 4. Step-down avoidance task
• 5. Radial 8-arm maze test
• 6. Tissue preparation
• 7. BrdU immunohistochemistry
• 8. RNA isolation and RT-PCR
• 9. Data analysis
• Results
• 1. Effect of spatial learning and treadmill exercise on memory ability in step-down avoidance task
• 2. Effect of spatial learning and treadmill exercise on memory ability in radial 8-arm maze test
• 3. Effect of spatial learning and treadmill exercise on cell proliferation in the dentate gyrus of hippocampus in mice
• 4. Effect of spatial learning and treadmill exercise on the expression of BDNF mRNA in the hippocampus in mice
• Discussion
• Conclusion
• References

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