Guinea Pig Kisspeptin Neurons Are Depolarized by Leptin via Activation of TRPC Channels
Guinea Pig Kisspeptin Neurons Are Depolarized by Leptin via Activation of TRPC Channels
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DOI：
10.1210/en.2010-1285
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发表时间：
2011-04-01
期刊：
影响因子：
4.8
通讯作者：
Kelly, Martin J.
中科院分区：
文献类型：
--
作者：
Qiu, Jian;Fang, Yuan;Kelly, Martin J.
下丘脑kisspeptin神经元是驱动生殖功能的关键，但几乎没有什么是已知的内源性电生理特性和瘦素对它们的兴奋性的影响。因此，我们用雌性豚鼠脑片研究了内源性电导和瘦素对kisspeptin神经元的影响。我们针对弓形kisspeptin神经元使用可视化补丁全细胞记录和识别kisspeptin神经元使用kisspeptin或单细胞RT-PCR免疫细胞化学染色。我们还收获了分散的弓状神经元用于通道转录物表达的分析。Kisspeptin神经元表现出相对负的静息膜电位，80%的神经元表达起搏电流（h电流）和T型钙电流。此外，谷氨酸受体激动剂N-甲基D-天冬氨酸去极化和诱导kisspeptin神经元的爆发式放电。瘦素激活内向电流，使kisspeptin神经元去极化并增加（爆发）放电，但瘦素使NPY神经元超极化。镧，TRPC-4，-5通道激活剂，增强瘦素诱导的内向电流的170%。leptin激活的电流在-15 mV附近逆转，并被相对选择性的TRPC通道阻断剂2-APB消除。瘦素的作用也被Janus激酶抑制剂、磷脂酰肌醇3激酶抑制剂和磷脂酶C γ抑制剂阻断。此外，基于单细胞RT-PCR，这些神经元中的大多数表达TRPC 1和-5和磷脂酶C γ 1。因此，豚鼠kisspeptin神经元表达内源性起搏电流，瘦素通过激活TRPC通道兴奋这些神经元。瘦素对kisspeptin神经元的兴奋作用可能是调节不同营养状态下GnRH神经元兴奋驱动的关键。（内分泌学152：1503-1514，2011）
Hypothalamic kisspeptin neurons are critical for driving reproductive function, but virtually nothing is known about their endogenous electrophysiological properties and the effects of leptin on their excitability. Therefore, we used the slice preparation from female guinea pigs to study the endogenous conductances and the effects of leptin on kisspeptin neurons. We targeted the arcuate kisspeptin neurons using visualized-patch whole-cell recording and identified kisspeptin neurons using immuocytochemical staining for kisspeptin or single cell RT-PCR. We also harvested dispersed arcuate neurons for analysis of expression of channel transcripts. Kisspeptin neurons exhibited a relatively negative resting membrane potential, and eighty percent of the neurons expressed a pacemaker current (h-current) and a T-type Ca2+ current. Furthermore, the glutamate receptor agonist N-methyl D-aspartic acid depolarized and induced burst firing in kisspeptin neurons. Leptin activated an inward current that depolarized kisspeptin neurons and increased (burst) firing, but leptin hyperpolarized NPY neurons. Lanthanum, a TRPC-4,-5 channel activator, potentiated the leptin-induced inward current by 170%. The leptin-activated current reversed near -15 mV and was abrogated by the relatively selective TRPC channel blocker 2-APB. The leptin effects were also blocked by a Janus kinase inhibitor, a phosphatidylinositol 3 kinase inhibitor, and a phospholipase C gamma inhibitor. In addition, the majority of these neurons expressed TRPC1 and -5 and phospholipase C gamma 1 based on single cell RT-PCR. Therefore, guinea pig kisspeptin neurons express endogenous pacemaker currents, and leptin excites these neurons via activation of TRPC channels. The leptin excitatory effects on kisspeptin neurons may be critical for governing the excitatory drive to GnRH neurons during different nutritional states. (Endocrinology 152: 1503-1514, 2011)