Brandstätter R, Fait E, Hermann A
Department of Animal Physiology, University of Salzburg, Austria.
Neuroreport. 1995 Jul 31;6(11):1553-6. doi: 10.1097/00001756-199507310-00022.
In the teleost pineal organ light activates functional photoreceptors, which transmit electrical activity to the brain via axons of intermediate ganglion cells. To investigate whether acetylcholine plays a role in the transduction of pineal photoreceptor signals, extracellular recordings were performed from ganglion cells of intact superfused pineal organs of the rainbow trout. Bath-applied acetylcholine increased the spike discharge rate of 96% of achromatic ganglion cells in a dose-dependent manner. The light response curve of ganglion cells, which was obtained by plotting spike rate vs light intensity, was significantly shifted by acetylcholine to higher frequencies. Acetylcholine was also active if applied during synaptic blockade with low Ca2+/high Mg(2+)-medium, demonstrating the presence of cholinergic receptors at the ganglion cell level. These data represent the first demonstration of acetylcholine constituting a postsynaptic modulation of photoreceptor signals in the trout pineal organ.
在硬骨鱼的松果体器官中，光激活功能性光感受器，这些光感受器通过中间神经节细胞的轴突将电活动传递到大脑。为了研究乙酰胆碱是否在松果体光感受器信号的转导中起作用，对虹鳟鱼完整的、灌注的松果体器官的神经节细胞进行了细胞外记录。浴用乙酰胆碱以剂量依赖的方式增加了96%的无色神经节细胞的放电频率。通过绘制放电频率与光强度的关系得到的神经节细胞的光反应曲线，被乙酰胆碱显著地向更高频率移动。如果在低钙/高镁培养基的突触阻断期间应用乙酰胆碱，它也有活性，这表明在神经节细胞水平存在胆碱能受体。这些数据首次证明了乙酰胆碱在鳟鱼松果体器官中构成了光感受器信号的突触后调制。
