Conrad C D, Jackson J L, Wise L S
Department of Psychology, Box 1104, Arizona State University, Tempe, AZ 85287-1104, USA.
Neuroscience. 2004;125(3):759-67. doi: 10.1016/j.neuroscience.2004.01.049.
The purpose of this investigation was to assess the ability of the hippocampus to withstand a metabolic challenge following chronic stress. An N-methyl-d-aspartate receptor excitotoxin (ibotenic acid, IBO) was infused into the CA3 region of the hippocampus following a period of restraint for 6 h/day/21 days. Following the end of restraint when CA3 dendritic retraction persists (3 to 4 days), rats were infused with IBO (or vehicle) into the CA3 region of the hippocampus. Stressed male rats showed significantly more CA3 damage after IBO infusion relative to controls and the saline-infused side. Moreover, IBO-exacerbation of damage in males was not observed in the CA3 region 3 to 4 days after acute stress (6 h restraint), nor in the CA1 region after chronic stress. Females were also examined and chronic stress did not exacerbate IBO damage in the CA3 region. Overall, these results demonstrate that chronic stress compromises the ability of the hippocampus to withstand a metabolic challenge days after the chronic stress regimen has subsided in male rats. Whether the conditions surrounding CA3 dendritic retraction in females represents vulnerability is less clear and warrants further investigation.
本研究的目的是评估海马体在慢性应激后应对代谢挑战的能力。在每天6小时、持续21天的束缚期后，将N-甲基-D-天冬氨酸受体兴奋性毒素（鹅膏蕈氨酸，IBO）注入海马体的CA3区域。在束缚期结束且CA3树突回缩持续存在（3至4天）后，将IBO（或赋形剂）注入大鼠海马体的CA3区域。与对照组和注入生理盐水的一侧相比，应激雄性大鼠在注入IBO后CA3损伤明显更严重。此外，在急性应激（6小时束缚）后3至4天的CA3区域，以及慢性应激后的CA1区域，均未观察到雄性大鼠IBO加剧损伤的情况。对雌性大鼠也进行了检查，慢性应激并未加剧CA3区域的IBO损伤。总体而言，这些结果表明，在雄性大鼠中，慢性应激方案消退数天后，慢性应激会损害海马体应对代谢挑战的能力。雌性大鼠中CA3树突回缩周围的情况是否代表易损性尚不清楚，值得进一步研究。
