Andrew R D, Orchard I, Saleuddin A S
Cell Tissue Res. 1978 Jul 5;190(2):235-46. doi: 10.1007/BF00218172.
The topography of the neurosecretory system in the decapod eyestalk has not been precisely delineated with light microscopy. Cobalt iontophoresis and electron microscopy have proved useful in clarifying the microstructure of this system. The sinus gland (sg) of the crayfish eyestalk consists of aggregated axon terminals which end at or near the blood space. Iontophoresing cobalt back through the cut base of the sinus glands reveals proximal cell bodies in the eyestalk only in the X organ (Xo) region. Electron microscopy demonstrates that axons from about 115 neurosecretory cell bodies in the Xo form the Xo-sg tract. Intermingled with these Xo somata are smaller non-neurosecretory cell bodies which do not send axons into the sinus gland. One of these exhibits catecholamine fluorescence. Backfilling also reveals a second group of fibres which run from the brain along the optic tract and into the sinus gland. These brain-sg fibres are smaller in diameter than Xo-sg axons and lack neurosecretory vesicles. From these fibres collaterals extend into the eyestalk neuropil, especially in the proximity of the visual elements. The possible function of these non-neurosecretory processes within the sinus gland is discussed.
十足目动物眼柄中神经分泌系统的拓扑结构尚未通过光学显微镜精确描绘。钴离子透入法和电子显微镜已被证明有助于阐明该系统的微观结构。小龙虾眼柄的窦腺（sg）由聚集的轴突终末组成，这些终末在血腔处或其附近终止。通过窦腺的切断基部反向离子透入钴，仅在X器官（Xo）区域的眼柄中揭示近端细胞体。电子显微镜显示，来自Xo中约115个神经分泌细胞体的轴突形成Xo-sg束。与这些Xo体细胞混合的是较小的非神经分泌细胞体，它们不向窦腺发送轴突。其中一个呈现儿茶酚胺荧光。反向填充还揭示了第二组纤维，它们从大脑沿着视神经束延伸到窦腺。这些脑-sg纤维的直径比Xo-sg轴突小，并且缺乏神经分泌小泡。从这些纤维发出的侧支延伸到眼柄神经纤维网中，特别是在视觉元件附近。讨论了窦腺内这些非神经分泌过程的可能功能。
