Heat exposure in female rats elicits abnormal fear expression and cellular changes in prefrontal cortex and hippocampus
Heat exposure in female rats elicits abnormal fear expression and cellular changes in prefrontal cortex and hippocampus
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DOI：
10.1016/j.nlm.2014.05.004
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发表时间：
2014-11-01
影响因子：
2.7
通讯作者：
Shansky, Rebecca M.
中科院分区：
文献类型：
--
作者：
Gruene, Tina M.;Lipps, Jennifer;Shansky, Rebecca M.
尽管女性中恐惧相关疾病的患病率是女性的两倍，但调节和驱动恐惧表达的神经生物学因素很少在雌性动物中进行研究。恐惧条件反射和消退是解剖这些机制的有用工具，在这里，我们测试了环境操纵的影响——在动物住房设施中暴露在31摄氏度的温度下四天——对雌性大鼠的恐惧学习和记忆的影响。我们发现，在恐惧条件反射过程中，热暴露破坏了对音调的冻结，并在消退和消退恢复过程中引发了增强的冻结。我们还通过免疫组化方法检测了c-fos在消失恢复过程中前额叶皮层边缘下（IL）和边缘前（PL）区域的表达，发现热暴露诱导了从IL主导活性到PL主导活性的转换。最后，对海马CA3神经元棘的形态学分析显示，热暴露动物的棘头直径增加，这可能是这些动物观察到的持续冷冻的部分原因。总之，我们的数据表明，热暴露可以引起行为、生理和结构层面的变化，并为缺乏关于雌性动物恐惧过程的文献提供了补充。(C) 2014爱思唯尔公司版权所有。
Despite a twofold higher prevalence of fear-related disorders in women, the neurobiological factors that modulate and drive fear expression are rarely studied in female animals. Fear conditioning and extinction are useful tools for dissecting these mechanisms, and here we tested the effects of environmental manipulations - four days of exposure to 31 degrees C temperatures in the animal housing facility - on fear learning and memory exclusively in female rats. We found that heat exposure disrupted freezing to tone during fear conditioning, and elicited enhanced freezing during extinction and extinction retrieval. We also performed immunohistochemistry for c-fos expression in the infralimbic (IL) and prelimbic (PL) regions of the prefrontal cortex during extinction retrieval, and found that heat exposure induced a switch from IL-dominated activity to PL-dominated activity. Finally, morphological analysis of spines in hippocampal CA3 neurons revealed an increase in spine head diameter in heat-exposed animals, which may partly underlie the persistent freezing observed in these animals. Together, our data show that heat exposure can induce changes at behavioral, physiological, and structural levels, and add to a woefully lacking body of literature on fear processes in female animals. (C) 2014 Elsevier Inc. All rights reserved.