The Characteristics of Supramammillary Cells Projecting to the Hippocampus in Stress Response in the Rat
The Characteristics of Supramammillary Cells Projecting to the Hippocampus in Stress Response in the Rat
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DOI：
10.4196/kjpp.2012.16.1.17
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发表时间：
2012-02-01
影响因子：
2
通讯作者：
Shim, Insop
中科院分区：
文献类型：
--
作者：
Choi, Woong Ki;Wirtshafter, David;Shim, Insop
下丘脑-垂体-肾上腺皮质（HPA）轴是应激反应的中心介质。乳上区（SuM）在下丘脑结构中是相对独特的，因为它向海马区发送一个大的，直接的投影。研究表明，轻微的压力可以激活投射到海马体的SuM细胞。然而，这些细胞群在调节应激反应中的作用尚不清楚。本研究通过向海马内注射荧光逆行示踪剂氟金（FG），并利用免疫组化方法检测胆碱乙酰转移酶（ChAT）、促肾上腺皮质激素释放因子（CRF）、血清素（5-HT）、谷氨酸脱羧酶（GAD）、酪氨酸羟化酶（TH）和NADPH-d反应性，研究应激对投射到海马的不同SuM细胞群的影响。固定（IMO）应激（2小时）使SuM细胞ChAT-免疫反应性表达增加，CRF、5-HT、GAD、th -免疫反应性和一氧化氮(NO)-反应性有增加的趋势。53%的5-HT细胞、31%的ChAT细胞和56%的CRF细胞用海马逆行细胞双重染色。相比之下，少数向海马体投射的逆行标记细胞对多巴胺、γ -氨基丁酸（GABA）和NO有免疫反应。这些结果表明，SuM区域包含不同的细胞群，对压力有不同的反应。此外，研究结果表明，SuM核内投射到海马的5 -羟色胺能、胆碱能和促肾上腺皮质激素释放细胞可能在调节应激相关行为中起重要作用。
The hypothalamus-pituitary-adrenocortex (HPA) axis is the central mediator of the stress response. The supramammillary (SuM) region is relatively unique among the hypothalamic structures in that it sends a large, direct projection to the hippocampal formation. It has been shown that mild stress could activate the SuM cells that project to the hippocampus. However, the role of these cell populations in modulating the stress response is not known. The present study examined the effect of stress on different populations of SuM cells that project to the hippocampus by injecting the fluorescent retrograde tracer, fluorogold (FG), into the hippocampus and utilizing the immunohistochemistry of choline acetyltransferase (ChAT), corticotrophin releasing factor (CRF), serotonin (5-HT), glutamate decarboxylase (GAD), tyrosine hydroxylase (TH) and NADPH-d reactivity. Immobilization (IMO) stress (2 hr) produced an increase in the expression of ChAT- immunoreactivity, and tended to increase in CRF, 5-HT, GAD, TH-immunoreactivity and nitric oxide (NO)-reactivity in the SuM cells. Fifty-three percent of 5-HT, 31% of ChAT and 56% of CRF cells were double stained with retrograde cells from the hippocampus. By contrast, a few retrogradely labeled cells projecting to the hippocampus were immunoreactive for dopamine, gamma-aminobutyric acid (GABA) and NO. These results suggest that the SuM region contains distinct cell populations that differentially respond to stress. In addition, the findings suggest that serotonergic, cholinergic and corticotropin releasing cells projecting to the hippocampus within the SuM nucleus may play an important role in modulating stress-related behaviors.