Activation of a subpopulation of orexin/hypocretin-containing hypothalamic neurons by GABAA receptor-mediated inhibition of the nucleus accumbens shell, but not by exposure to a novel environment
Activation of a subpopulation of orexin/hypocretin-containing hypothalamic neurons by GABAA receptor-mediated inhibition of the nucleus accumbens shell, but not by exposure to a novel environment
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DOI：
10.1111/j.1460-9568.2004.03093.x
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发表时间：
2004-01-01
影响因子：
3.4
通讯作者：
Kelley, AE
中科院分区：
文献类型：
--
作者：
Baldo, BA;Gual-Bonilla, L;Kelley, AE
γ-氨基丁酸（GABA）（A）受体刺激在丘脑背外侧核壳产生强烈的摄食过多，并增加Fos在下丘脑外侧的表达。为了探索下丘脑食欲素/下丘脑泌素或黑色素浓缩的神经元在这种作用中的参与，将GABA（A）激动剂蝇蕈醇（0，50 ng）直接注入大鼠的延髓核壳; 90 min后，收集它们的大脑，随后进行免疫组织化学处理。一组暴露于一个新的环境，包括评估Fos表达变化的特异性方面的一般觉醒。通过下丘脑的交替切片对食欲素/下丘脑泌素-Fos或黑色素浓缩酶-Fos组合进行双重染色。内壳蝇蕈醇治疗显着增加的百分比，食欲素/下丘脑泌素含有神经元表达Fos的外侧，但不内侧，部分穹窿周围/外侧下丘脑区。无论治疗条件，下丘脑内侧部分的食欲素/下丘脑泌素的神经元表达Fos相对于位于更外侧的细胞的百分比更大。没有一个操作增加Fos表达在黑色素浓集的免疫反应神经元。蝇蕈醇治疗还显著增加了弓状核中的Fos表达，弓状核连接丘脑外侧/穹窿周围的下丘脑区域。因此，食欲素/下丘脑外侧区的含下丘脑的神经元，沿着与弓状核中的细胞一起，在促食欲的药理学操作后显示Fos表达的阶段性增加，但在与暴露于新环境相关的高度觉醒后程度较低。
gamma-Amino butyric acid (GABA)(A) receptor stimulation in the nucleus accumbens shell produces intense hyperphagia in rats and increases Fos expression in the lateral hypothalamus. To explore the involvement of hypothalamic orexin/hypocretin- or melanin concentrating hormone-immunoreactive neurons in this effect, the GABA(A) agonist, muscimol (0, 50 ng), was infused directly into the nucleus accumbens shell of rats; 90 min later, their brains were collected and subsequently processed for immunohistochemistry. A group exposed to a novel environment was included to evaluate the specificity of Fos expression changes with regard to general arousal. Alternating sections through the hypothalamus were double-stained for orexin/hypocretin-Fos or melanin concentrating hormone-Fos combinations. Intra-accumbens shell muscimol treatment significantly increased the percentage of orexin/hypocretin-containing neurons expressing Fos in the lateral, but not medial, portion of the perifornical/lateral hypothalamic area. Regardless of treatment condition, greater percentages of orexin/hypocretin-containing neurons in the medial portion of the hypothalamus expressed Fos relative to cells located more laterally. None of the manipulations increased Fos expression in melanin concentrating hormone-immunoreactive neurons. Muscimol treatment also markedly increased Fos expression in the arcuate nucleus, which connects reciprocally to the lateral/perifornical hypothalamic area. Thus, orexin/hypocretin-containing neurons in lateral sectors of the hypothalamus, along with cells in the arcuate nucleus, display phasic increases in Fos expression after an orexigenic pharmacological manipulation of the nucleus accumbens shell, but to a lesser degree after the heightened arousal associated with exposure to a novel environment.