Fujimoto Tetsuya, Aou Shuji
Department of Physiology, Osaka Dental University.
Department of Human Intelligence Systems, Kyushu Institute of Technology.
J Toxicol Sci. 2018;43(9):531-536. doi: 10.2131/jts.43.531.
Perinatal exposure to bisphenol A (BPA) causes several alterations in brain function and behavior. In previous studies, we showed that prenatal treatment with low-level BPA impaired gender-specific behavior, enhanced depression-like behavior, and augmented behavioral responses to predator odor in rats. On this premise, we hypothesized that BPA-treated rats were more susceptible to predator odor stress. To test the potential neural mechanism underlying this effect, we conducted an electrophysiological study of neurons in the medial amygdala-a regional component of the olfactory pathway with high estrogen and androgen receptor expression, and thus a potential target of BPA-in rats exposed to BPA. Extracellular recordings were obtained during the presentation of 3 plant odors and 3 predator odorants. Odor-responsive neurons in BPA-exposed rats showed greater activity in response to fox odor than did those in control rats. This finding complements the results of our previous behavioral study in which BPA-exposed rats exhibited enhanced avoidance behavior in response to fox odor. Given the close relationship between olfactory signaling and the stress response system, we suspect that BPA modifies the olfactory pathway at the level of the medial amygdala and thus modulates the corresponding stress response.
围产期暴露于双酚A（BPA）会导致大脑功能和行为的多种改变。在先前的研究中，我们表明，低剂量BPA的产前治疗会损害大鼠的性别特异性行为，增强类似抑郁的行为，并增强对捕食者气味的行为反应。在此前提下，我们假设经BPA处理的大鼠对捕食者气味应激更敏感。为了测试这种效应背后的潜在神经机制，我们对内侧杏仁核（嗅觉通路的一个区域成分，雌激素和雄激素受体表达水平高，因此是BPA的一个潜在靶点）中的神经元进行了电生理研究，这些大鼠暴露于BPA。在呈现3种植物气味和3种捕食者气味剂的过程中进行细胞外记录。与对照大鼠相比，暴露于BPA的大鼠中对气味有反应的神经元对狐狸气味的反应表现出更大的活性。这一发现补充了我们先前行为研究的结果，即在该研究中，暴露于BPA的大鼠对狐狸气味表现出增强的回避行为。鉴于嗅觉信号与应激反应系统之间的密切关系，我们怀疑BPA在内侧杏仁核水平改变了嗅觉通路，从而调节了相应的应激反应。
