Carson K A, Burd G D
J Comp Neurol. 1980 Jun;191(3):353-71. doi: 10.1002/cne.901910304.
Experiments were conducted to examine by light and electron microscopy the localization of acetylcholinesterase (AChE) in the main (MOB) and accessory (AOB) olfactory bulbs of the normal mouse. Evidence from the literature for cholinergic innervation of the mammalian olfactory bulb was then assessed in light of possible correlation between reported sites of termination of centrifugal fibers to the olfactory bulb and the localization of AChE. AChE-positive nerve fibers were concentrated in the periglomerular region and internal plexiform layer of the MOB. Stained fibers were also present in the granule cell, mitral cell, and external plexiform layers as well as within glomeruli. A few neurons in all layers of the MOB contained AChE reaction product. Unlike the MOB, AChE-positive fibers were not present in the glomerular layer of the AOB. AChE-positive fibers were concentrated in the inner plexiform layer, whereas fewer stained fibers were observed in the external plexiform and mitral cell layer and granule cell layer. Lightly stained neurons were found in the deeper portions of the external plexiform and mitral cell layer and granule cell layer. Ultrastructurally, AChE reaction product in the MOB and AOB was predominantly associated with small unmyelinated axons. Reaction product was also observed adjacent to axon terminals and dendrites. Occasionally within the MOB, AChE activity was found within periglomerular, tufted, short-axon, mitral, and granule cells. In the AOB, however, intracellular AChE activity was observed within some mitral/tufted cells and only a few granule cells. In conclusion, the AChE reaction product was mainly associated with axons in regions of the MOB where centrifugal fibers have been reported. Accessory olfactory bulb AChE localization was different from that of the MOB, suggesting a different pattern of cholinergic input to the AOB. The small amounts and sites of intraneuronal AChE reaction product in cells of the olfactory bulb indicate cholinoceptive rather than cholinergic function.
进行了实验，通过光学显微镜和电子显微镜检查正常小鼠主嗅球（MOB）和副嗅球（AOB）中乙酰胆碱酯酶（AChE）的定位。然后根据离心纤维终止于嗅球的报道部位与AChE定位之间可能存在的相关性，评估了文献中关于哺乳动物嗅球胆碱能神经支配的证据。AChE阳性神经纤维集中在MOB的球周区域和内丛状层。染色的纤维也存在于颗粒细胞层、主细胞层和外丛状层以及嗅小球内。MOB各层中的一些神经元含有AChE反应产物。与MOB不同，AChE阳性纤维不存在于AOB的嗅小球层。AChE阳性纤维集中在内丛状层，而在外丛状层、主细胞层和颗粒细胞层中观察到的染色纤维较少。在较深的外丛状层、主细胞层和颗粒细胞层中发现了轻度染色的神经元。在超微结构上，MOB和AOB中的AChE反应产物主要与小的无髓轴突相关。在轴突终末和树突附近也观察到反应产物。偶尔在MOB内，在球周细胞、簇状细胞、短轴突细胞、主细胞和颗粒细胞内发现AChE活性。然而，在AOB中，在一些主/簇状细胞和仅少数颗粒细胞内观察到细胞内AChE活性。总之，AChE反应产物主要与MOB中报道有离心纤维的区域的轴突相关。副嗅球的AChE定位与MOB不同，表明向AOB的胆碱能输入模式不同。嗅球细胞内AChE反应产物的少量存在和部位表明其具有胆碱感受功能而非胆碱能功能。
