Smithson K G, Weiss M L, Hatton G I
Department of Physiology, Michigan State University, East Lansing 48824-1117.
Brain Res Bull. 1992 Aug;29(2):209-20. doi: 10.1016/0361-9230(92)90028-v.
Our earlier electrophysiological work provided evidence of a direct input to the supraoptic nucleus (SON) from the olfactory bulbs; however, these experiments could not determine if the input originated in the main and/or accessory portions of the olfactory bulb. Here, a connection between the accessory olfactory bulb (AOB) and the SON of the rat was examined using a combination of anatomic techniques. We employed neurophysin immunocytochemistry to delineate the morphological boundaries of the SON and the proximal arborizations of supraoptic dendrites. Accessory olfactory bulb efferents to the SON were studied by injection of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) into the AOB. The distribution of retrogradely labeled cells within the AOB was also determined after injection of either rhodamine-labeled latex microspheres (rhodamine beads) or Fluoro-Gold (FG) into the SON. Neurophysin immunocytochemistry revealed that SON dendrites extended beyond the generally accepted boundaries of the nucleus, coursing ventrolaterally along the surface of the periamygdaloid cortex. Anterograde tract tracing with WGA-HRP labeled AOB efferents including a dense plexus of terminals and fibers around the ipsilateral SON along the path of the ventrally projecting dendrites. Injections of retrograde tracers into the SON resulted in rhodamine bead or FG labeling of mitral cells throughout the ipsilateral AOB. Taken together, these anatomic studies suggest a direct projection from the accessory olfactory bulb to the SON of the rat and thus a vomeronasal organ to SON pathway.
我们早期的电生理研究提供了嗅球向视上核（SON）有直接输入的证据；然而，这些实验无法确定该输入是否起源于嗅球的主部和/或副部。在此，我们结合解剖学技术研究了大鼠副嗅球（AOB）与视上核之间的联系。我们采用神经垂体素免疫细胞化学来描绘视上核的形态边界以及视上树突的近端分支。通过将与辣根过氧化物酶（WGA-HRP）偶联的小麦胚芽凝集素注入副嗅球来研究其向视上核的传出纤维。在将罗丹明标记的乳胶微球（罗丹明珠）或荧光金（FG）注入视上核后，还确定了副嗅球内逆行标记细胞的分布。神经垂体素免疫细胞化学显示，视上核的树突延伸超出了该核通常公认的边界，沿着杏仁周皮质表面向腹外侧走行。用WGA-HRP进行的顺行束路追踪标记了副嗅球的传出纤维，包括沿着腹侧投射树突路径在同侧视上核周围有密集的终末和纤维丛。将逆行示踪剂注入视上核导致同侧整个副嗅球内的二尖瓣细胞被罗丹明珠或FG标记。综上所述，这些解剖学研究表明大鼠副嗅球向视上核有直接投射，从而存在一个从犁鼻器到视上核的通路。
