Meissl H, Martin C, Tabata M
Max-Planck-Institut fur Physiologische and Klinische Forschung, Federal Republic of Germany.
J Comp Physiol A. 1990 Nov;167(5):641-8. doi: 10.1007/BF00192657.
Hormonal and neural signals transmitted from the pineal organ to the brain in cold-blooded vertebrates presumably convert information about the ambient illumination into signals which may be used to mediate photoperiodic and circadian responses. The possible intrapineal function of melatonin was investigated by recording intra- and extracellularly from photoreceptors and second-order neurons in the isolated superfused pineal organ of the trout (Salmo gairdneri). Melatonin added through the perfusion bath to the explanted pineal organ caused a dose-related and reversible inhibition of ganglion cells of the luminance type whereas the hormone did not significantly affect the membrane potential of photoreceptors and their light-evoked response. The observed effects seem to be independent from photoperiod and adaptation conditions. These results suggest that melatonin provides a feedforward signal to intrapineal neurons regulating the neural output of the organ.
在冷血脊椎动物中，从松果体器官传递至大脑的激素信号和神经信号大概会将有关环境光照的信息转化为可用于介导光周期和昼夜节律反应的信号。通过在离体的、经灌注的虹鳟（Salmo gairdneri）松果体器官中的光感受器和二级神经元进行细胞内和细胞外记录，研究了褪黑素在松果体内可能的功能。通过灌注浴将褪黑素添加到离体的松果体器官中，会导致亮度型神经节细胞出现剂量相关且可逆的抑制，而该激素对光感受器的膜电位及其光诱发反应没有显著影响。观察到的这些效应似乎与光周期和适应条件无关。这些结果表明，褪黑素为松果体内调节该器官神经输出的神经元提供了一个前馈信号。
