Westfall J A, Landers D D, McCallum J D
Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506-5602, USA.
J Morphol. 1999 Aug;241(2):165-73. doi: 10.1002/(SICI)1097-4687(199908)241:2<165::AID-JMOR6>3.0.CO;2-6.
Using transmission electron microscopy of serially sectioned tentacles from the sea anemone Aiptasia pallida, we located and characterized two types of neuro-spirocyte synapses. Clear vesicles were observed at 10 synapses and dense-cored vesicles at five synapses. The diameters of vesicles at each neuro-spirocyte synapse were averaged; clear vesicles ranged from 49-89 nm in diameter, whereas the dense-cored vesicles ranged from 97-120 nm in diameter. One sequential pair of synapses included a neuro-spirocyte synapse with clear vesicles (81 nm) and a neuro-neuronal synapse with dense-cored vesicles (168 nm). A second synapse on the same cell had dense-cored vesicles (103 nm). An Antho-RFamide-labeled ganglion cell and three different neurites were observed adjacent to spirocytes, but no neuro-spirocyte synapses were present. Many of the spirocytes also were immunoreactive to Antho-RFamide. The presence of sequential neuro-neuro-spirocyte synapses suggests that synaptic modulation may be involved in the neural control of spirocyst discharge. The occurrence of either dense-cored or clear vesicles at neuro-spirocyte synapses suggests that at least two types of neurotransmitter substances control the discharge of spirocysts in sea anemones.
利用透射电子显微镜对海葵苍白艾氏海葵的触手连续切片进行观察，我们定位并描述了两种类型的神经-螺旋细胞突触。在10个突触处观察到清亮小泡，在5个突触处观察到致密核心小泡。对每个神经-螺旋细胞突触处小泡的直径进行了平均；清亮小泡直径范围为49 - 89纳米，而致密核心小泡直径范围为97 - 120纳米。一对连续的突触包括一个有清亮小泡（81纳米）的神经-螺旋细胞突触和一个有致密核心小泡（168纳米）的神经-神经突触。同一细胞上的第二个突触有致密核心小泡（103纳米）。在螺旋细胞附近观察到一个被Antho - RFamide标记的神经节细胞和三种不同的神经突，但不存在神经-螺旋细胞突触。许多螺旋细胞对Antho - RFamide也有免疫反应性。连续的神经-神经-螺旋细胞突触的存在表明突触调制可能参与了刺丝囊排放的神经控制。神经-螺旋细胞突触处出现致密核心或清亮小泡表明至少有两种类型的神经递质物质控制着海葵中刺丝囊的排放。
