Departments of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Korea.
PLoS One. 2013 Dec 18;8(12):e85189. doi: 10.1371/journal.pone.0085189. eCollection 2013.
In both vertebrates and invertebrates, Transient Receptor Potential (TRP) channels are expressed in sensory neurons and mediate environmental stimuli such as light, sound, temperature, and taste. Some of these channels, however, are expressed only in the brain and their functions remain incompletely understood. Using the GAL4/UAS binary system with a line in which the GAL4 had been knocked into the trpA1 locus in Drosophila, we recently reported new insights into TRPA1 localization and function, including its expression in approximately 15% of all circadian neurons. TRPA1 is expressed in lateral posterior neurons (LPNs), which are known to be highly sensitive to entrainment by temperature cycles. Here, I used the bacterial sodium channel, NaChBac, to examine the effects of altering the electrical properties of trpA1 neurons on circadian rhythms. My results indicate that circadian activity of the flies in the morning, daytime, and evening was affected in a temperature-dependent manner following TRPA1 neuronal activation. Remarkably, TRPA1 neuron activation in flies kept at 18°C impacted the morning peak of circadian activity even though TRPA1 is not expressed in morning cells. Taken together, these results suggest that the activation of TRPA1-expressing neurons may differentially coordinate light/dark circadian entrainment, depending on the temperature.
在脊椎动物和无脊椎动物中，瞬时受体电位 (TRP) 通道表达于感觉神经元中，并介导环境刺激，如光、声、温度和味觉。然而，其中一些通道仅在大脑中表达，其功能仍不完全了解。使用 GAL4/UAS 双元系统，其中 GAL4 已被敲入果蝇中的 trpA1 基因座，我们最近报告了对 TRPA1 定位和功能的新见解，包括其在大约 15%的所有生物钟神经元中的表达。TRPA1 在侧向后神经元 (LPN) 中表达，已知 LPN 对温度循环的节律性适应非常敏感。在这里，我使用细菌钠离子通道 NaChBac 来研究改变 trpA1 神经元的电特性对生物钟节律的影响。我的结果表明，TRPA1 神经元激活后，果蝇在清晨、白天和晚上的生物钟活动以温度依赖的方式受到影响。值得注意的是，即使 TRPA1 在清晨细胞中不表达，在 18°C 下保持的果蝇中 TRPA1 神经元的激活也会影响生物钟活动的清晨高峰。总之，这些结果表明，TRPA1 表达神经元的激活可能根据温度差异协调光/暗生物钟的节律性适应。
