Meissl H, Yáñez J
Max-Planck-Institute for Physiological and Clinical Research, W.G. Kerckhoff-Institute, Bad Nauheim, Germany,
Neurosci Lett. 1996 Mar 22;207(1):37-40. doi: 10.1016/0304-3940(96)12482-4.
The pineal organ of teleost fish receives photic information directly through specialized photoreceptor cells that transmit their light response to second-order neurons and respond also with an endocrine light-dependent melatonin signal. In the present study we have analyzed the action of diazepam, a full agonist of the benzodiazepine receptor, on the photic regulation of the endocrine melatonin response of cultured trout pineal organs. Melatonin release of explanted pineal organs was clearly dependent on the irradiance of incident light with a maximum change during mesopic illuminations. Addition of diazepam to the superfusion medium significantly increased melatonin production in the mesopic and partly in the photopic range of illumination, without showing clear effects in the dark-adapted organ. Flumazenil, a central acting benzodiazepine antagonist, slightly reduced melatonin secretion. The action of diazepam appears to be comparable to a dark-pulse in the mesopic range of illuminations.
硬骨鱼的松果体器官通过特殊的光感受器细胞直接接收光信息，这些光感受器细胞将其光反应传递给二级神经元，并通过依赖光的褪黑素内分泌信号做出反应。在本研究中，我们分析了苯二氮䓬受体的完全激动剂地西泮对培养的鳟鱼松果体器官内分泌褪黑素反应的光调节作用。离体松果体器官的褪黑素释放明显依赖于入射光的辐照度，在中间视觉照明期间变化最大。向灌注培养基中添加地西泮可显著增加中间视觉和部分明视觉照明范围内的褪黑素生成，而在暗适应器官中未显示明显效果。中枢作用的苯二氮䓬拮抗剂氟马西尼可轻微降低褪黑素分泌。地西泮的作用在中间视觉照明范围内似乎与暗脉冲相当。
