Connectivity from OR37 expressing olfactory sensory neurons to distinct cell types in the hypothalamus
Connectivity from OR37 expressing olfactory sensory neurons to distinct cell types in the hypothalamus
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DOI：
10.3389/fncir.2012.00084
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发表时间：
2012-11-16
影响因子：
3.5
通讯作者：
Strotmann, Joerg
中科院分区：
文献类型：
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作者：
Bader, Andrea;Klein, Bettina;Strotmann, Joerg
嗅觉感觉神经元（OSN）表达来自气味受体（OR）基因的OR 37亚家族的成员，其以独特的单肾小球方式连接到主嗅球（MOB）;从这些肾小球存在到高级脑中心的非典型连接。在本研究中，我们已经调查了Dil和跨突触追踪的方法如何连接模式，从这些肾小球到不同的下丘脑核的组织。将Dil应用于含有OR 37肾小球的球的腹侧域导致室旁核（PVN）和下丘脑视上核（SO）内的纤维的标记;这些纤维中的一些被静脉曲张样结构覆盖。在这些细胞核中未检测到Dil标记的细胞胞体。这些数据表明，起源于MOB的OR 37区域的投射神经元形成到这些核的直接连接。进一步表征这些核中由跨突触示踪剂WGA标记的细胞。它们在室旁核的分布模式使人想起产生不同神经肽的细胞。双标记实验证实，它们含有加压素，但不含有相关的神经肽催产素。形态学分析表明，它们由大细胞和小细胞组成。在SO的WGA阳性细胞的比较研究表明，这些是加压素阳性，以及，而催产素生产细胞的这个核也不含跨突触示踪剂。总之，这些数据证明了从表达OR 37的感觉神经元到具有相同神经肽含量的不同下丘脑神经元的连通性。
Olfactory sensory neurons (OSNs) which express a member from the OR37 subfamily of odorant receptor (OR) genes are wired to the main olfactory bulb (MOB) in a unique monoglomerular fashion; from these glomeruli an untypical connectivity into higher brain centers exists. In the present study we have investigated by Dil and transsynaptic tracing approaches how the connection pattern from these glomeruli into distinct hypothalamic nuclei is organized. The application of Dil onto the ventral domain of the bulb which harbors the OR37 glomeruli resulted in the labeling of fibers within the paraventricular nucleus (PVN) and supraoptic nucleus (SO) of the hypothalamus; some of these fibers were covered with varicose-like structures. No Dil-labeled cell somata were detectable in these nuclei. The data indicate that projection neurons which originate in the OR37 region of the MOB form direct connections into these nuclei. The cells that were labeled by the transsynaptic tracer WGA in these nuclei were further characterized. Their distribution pattern in the paraventricular nucleus was reminiscent of cells which produce distinct neuropeptides. Double labeling experiments confirmed that they contained vasopressin, but not the related neuropeptide oxytocin. Morphological analysis revealed that they comprise of magno- and parvocellular cells. A comparative investigation of the WGA-positive cells in the SO demonstrated that these were vasopressin-positive, as well, whereas oxytocin-producing cells of this nucleus also contained no transsynaptic tracer. Together, the data demonstrates a connectivity from OR37 expressing sensory neurons to distinct hypothalamic neurons with the same neuropeptide content.