Section of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyou-ku, Tokyo 113-8519, Japan.
Neurosci Res. 2011 Oct;71(2):161-7. doi: 10.1016/j.neures.2011.06.006. Epub 2011 Jun 16.
Exposure to novelty, a mild psychological stressor, induces neuronal activations in the hippocampus of rodents, which may play an important role in the adaptation to stress. We examined the changes in three parameters, i.e., gene expression in the hippocampus using a RT-PCR method, corticosterone and motor activity, in mice exposed to a new environment for 120min. A sharp and short-lasting increase in the gene expression of a set of stress-related genes previously reported, e.g., Fos and Nr4a1, was observed during the stress, with a similar pattern of changes in corticosterone. The motor activity gradually decreased during the novelty stress, indicating a process of adaptation to the new environment. In addition, in order to minimize the effects of elevated adrenal hormones by the stress, we carried out experiments on adrenalectomized (ADX) mice. However, the adrenalectomy produced minimal changes in the pattern and the magnitude of the gene response after the stress, while the motor activity showed a relatively slower pattern of adaptation in the ADX mice. Hence, the present study suggests that there was a coordinated adaptation process to the new environment in mice, and that the transcriptional response was mediated by neuronal networks rather than by adrenal hormones.
暴露于新奇事物，一种轻度的心理应激源，会引起啮齿动物海马神经元的激活，这可能在应激适应中发挥重要作用。我们研究了三组参数的变化：使用 RT-PCR 方法检测海马中的基因表达、皮质酮和运动活性，以评估暴露于新环境 120 分钟的小鼠的变化。应激过程中观察到一组应激相关基因（如 Fos 和 Nr4a1）的基因表达急剧而短暂的增加，皮质酮也呈现出相似的变化模式。运动活性在新奇应激过程中逐渐下降，表明对新环境的适应过程。此外，为了将应激引起的肾上腺激素升高的影响最小化，我们在肾上腺切除（ADX）小鼠上进行了实验。然而，应激后基因反应的模式和幅度的肾上腺切除术产生的变化很小，而 ADX 小鼠的运动活性适应模式相对较慢。因此，本研究表明，小鼠对新环境存在协调的适应过程，转录反应是由神经元网络介导的，而不是由肾上腺激素介导的。
