Mapping of serotonin, dopamine, and histamine in relation to different clock neurons in the brain of Drosophila
Mapping of serotonin, dopamine, and histamine in relation to different clock neurons in the brain of Drosophila
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DOI：
10.1002/cne.20807
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发表时间：
2006-01-10
影响因子：
2.5
通讯作者：
Nässel, DR
中科院分区：
文献类型：
--
作者：
Hamasaka, Y;Nässel, DR
几组时钟神经元协同作用，产生黑腹果蝇的昼夜活动节律。为了扩展关于时钟电路中神经递质的知识，我们分析了一些生物胺的分布与所识别的时钟神经元的关系。这是通过使用时钟神经元特异性GAL4株来驱动绿色荧光蛋白(GFP)的表达，结合免疫细胞化学和抗5-羟色胺、组胺和酪氨酸羟基酶(针对多巴胺)的血清来实现的。在幼年和成人脑中，5-羟色胺免疫反应(-IR)神经元突起靠近主要时钟神经元S-LN(V)S的树突和背侧终末。此外，1-LNV时钟神经元的终末和5-羟色胺能突起汇聚在远端延髓。在幼虫脑中，没有组胺(HA)-IR过程与S-LN(V)S接触，但可能影响背时钟神经元DN2.在成人脑中，眼外小孔光感受器的HA-IR轴突终止于LN(V)S的树突分支。在幼虫和成人脑中，在S-LNV的背侧终末附近可见少量酪氨酸羟化酶(TH)-IR突起，但未见其树突。在成人，TH-IR突起也与1-LN(V)S的远端延髓分支汇聚。在不同的时钟神经元中都没有检测到单胺类物质。通过用成像系统监测携带Fura-2的游离绿色荧光蛋白标记的S-LN(V)S幼虫细胞内钙离子水平，我们证明了5-羟色胺诱导的钙离子浓度呈剂量依赖性下降。因此，5-羟色胺能神经元在幼虫脑中的S-LNV上形成功能性输入，可能在成年脑中也是如此。
Several sets of clock neurons cooperate to generate circadian activity rhythms in Drosophila melanogaster. To extend the knowledge on neurotransmitters in the clock circuitry, we analyzed the distribution of some biogenic amines in relation to identified clock neurons. This was accomplished by employing clock neuron-specific GAL4 lines driving green fluorescent protein (GFP) expression, combined with immunocytochemistry with antisera against serotonin, histamine, and tyrosine hydroxylase (for dopamine). In the larval and adult brain, serotonin-immunoreactive (-IR) neuron processes are in close proximity of both the dendrites and the dorsal terminals of the major clock neurons, the s-LN(v)s. Additionally, the terminals of the 1-LNv clock neurons and serotonergic processes converge in the distal medulla. No histamine (HA)-IR processes contact the s-LN(v)s in the larval brain, but possibly impinge on the dorsal clock neurons, DN2. In the adult brain, HA-IR axons of the extraocular eyelet photoreceptors terminate on the dendritic branches of the LN(v)s. A few tyrosine hydroxylase (TH)-IR processes were seen close to the dorsal terminals of the s-LNvs, but not their dendrites, in the larval and adult brain. TH-IR processes also converge with the distal medulla branches of the 1-LN(v)s in adults. None of the monoamines was detectable in the different clock neurons. By using an imaging system to monitor intracellular Ca2+ levels in dissociated GFP-labeled larval s-LN(v)s, loaded with Fura-2, we demonstrated that application of serotonin induced dose-dependent decreases in Ca2+. Thus, serotonergic neurons form functional inputs on the s-LNvs in the larval brain and possibly also in adults.