Vigh B, Debreceni K, Manzano e Silva M J
Photoneuroendocrine Laboratory, Second Department of Anatomy, Histology and Embryology, Budapest, Hungary.
Acta Biol Hung. 1995;46(1):99-106.
The localization of immunoreactive glutamate and aspartate was compared in the pineal organ and retina of various vertebrates (Raja clavata, Carassius auratus, Salvelinus alpinus, Triturus vulgaris, Triturus cristatus, Lacerta muralis, Lacerta agilis, Lacerta viridis, Columbia livia and white leghorn chicken) by postembedding immunoelectron microscopy. Immunoreaction of both excitatory amino acids was detected in the pinealocytes in a localization similar to that of retinal photoreceptors. The reaction was intense in the axonal processes of pinealocytes as well as retinal rods and cones, further in their terminals on secondary pineal and retinal neurons. Subsequent immunoreaction on the same section showed a colocalization of glutamate and aspartate. The accumulation of these amino acids in the presynaptic part of pinealocytes suggests that they act as synaptic mediators in the neural efferentation of the pineal organ. In reptiles and birds where the hormonal efferentation of the pineal is well developed, glutamate and aspartate was also found to be accumulated in neuroendocrine terminals of pinealocytes. Therefore, glutamate and aspartate may have a role in both the hormonal and neural efferentation of the pineal organ.
通过包埋后免疫电子显微镜技术，比较了多种脊椎动物（扁鲨、鲫鱼、北极红点鲑、普通蝾螈、有冠蝾螈、壁蜥、捷蜥蜴、绿蜥蜴、家鸽和白来航鸡）松果体器官和视网膜中免疫反应性谷氨酸和天冬氨酸的定位。在松果体细胞中检测到这两种兴奋性氨基酸的免疫反应，其定位与视网膜光感受器相似。在松果体细胞的轴突以及视网膜视杆和视锥细胞中反应强烈，在它们与次级松果体和视网膜神经元的终末中反应更强。同一切片上随后的免疫反应显示谷氨酸和天冬氨酸共定位。这些氨基酸在松果体细胞突触前部分的积累表明它们在松果体器官的神经传出中充当突触介质。在松果体激素传出发达的爬行动物和鸟类中，也发现谷氨酸和天冬氨酸积累在松果体细胞的神经内分泌终末。因此，谷氨酸和天冬氨酸可能在松果体器官的激素和神经传出中都起作用。
