Kadota Y, Pettigrew K D, Brightman M W
Laboratory of Neurobiology, NINDS, National Institutes of Health, Bethesda, Maryland 20892.
Synapse. 1990;5(3):175-89. doi: 10.1002/syn.890050303.
A major target of neurosecretory axons (NSA) is the basal lamina around fenestrated blood vessels (FBV) in the neural lobe of the pituitary gland. We have posed the question of whether there is neurovascular specificity. Do mature, regenerating NSA terminate selectively on the FBV of the neural lobe compared with the FBV of other tissues that normally are not innervated by NSA? Three types of tissue were transplanted between inbred Fisher rats. Fragments, about 1 mm3, of pineal, adrenal medulla, and neural lobe were grafted bilaterally to the hypothalamic, retro-chiasmatic area, which includes bundles of NSA from supraoptic and paraventricular neurosecretory nuclei exclusively, but no FBV. Two and 4 weeks later, the grafts were prepared for the immunohistochemical localization of NSA and for electron microscopy. NSA-FBV proximity was measured, and the number of NSA, FBV, and of NSA-FBV associations was counted per surface area of each graft. Regenerating NSA can associate as closely with FBV of other tissues as they can with the FBV of the neural lobe. There does not appear to be specificity with respect to the closeness of association between neurosecretory terminals and fenestrated capillaries. However, the number of these associations is greater in neural lobe grafts than in adrenal or pineal grafts at 4 weeks. The number of FBV is also greatest in neural lobe grafts at this time, an increase that would provide a greater opportunity for NSA-FBV associations.
神经分泌轴突（NSA）的一个主要靶点是垂体神经叶中窗孔状血管（FBV）周围的基膜。我们提出了一个问题，即是否存在神经血管特异性。与通常不受NSA支配的其他组织的FBV相比，成熟的、再生的NSA是否会选择性地终止于神经叶的FBV？在近交系费希尔大鼠之间进行了三种组织的移植。将约1立方毫米的松果体、肾上腺髓质和神经叶碎片双侧移植到下丘脑视交叉后区域，该区域仅包含来自视上核和室旁神经分泌核的NSA束，但没有FBV。2周和4周后，对移植物进行处理，用于NSA的免疫组织化学定位和电子显微镜检查。测量NSA与FBV的接近程度，并计算每个移植物单位表面积内NSA、FBV以及NSA-FBV关联的数量。再生的NSA与其他组织的FBV的关联程度与它们与神经叶的FBV的关联程度相同。神经分泌终末与窗孔状毛细血管之间的关联紧密程度似乎不存在特异性。然而，在4周时，神经叶移植物中这些关联的数量比肾上腺或松果体移植物中的更多。此时神经叶移植物中FBV的数量也最多，这种增加将为NSA-FBV关联提供更多机会。
