Organization of hypocretin/orexin efferents to locus coeruleus and basal forebrain arousal-related structures
Organization of hypocretin/orexin efferents to locus coeruleus and basal forebrain arousal-related structures
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DOI：
10.1002/cne.20369
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发表时间：
2005-01-10
影响因子：
2.5
通讯作者：
Berridge, CW
中科院分区：
文献类型：
--
作者：
España, RA;Reis, KM;Berridge, CW
下丘脑分泌素/食欲素神经元产生一个广泛的投射系统，其部分神经支配与行为状态调节相关的多个区域。这些区域包括蓝斑、内隔区、内视前区和无名物质。有证据表明，下丘脑分泌素通过这些终端场的作用来调节行为状态。为了更好地理解下丘脑分泌素依赖性行为状态调节的电路，本研究表征了存在的程度：1)下丘脑分泌素向基底前脑和脑干觉醒相关区域的侧化，2)基底前脑和脑干投射下丘脑分泌素神经元的地形组织，以及3)单个下丘脑分泌素神经元向这些觉醒相关终端场的侧化。这些研究利用免疫组织化学联合鉴定下丘脑分泌素神经元，从蓝斑、内侧视前区、内侧隔区和无名质进行单次或双次逆行追踪。结果表明，大约80%的下丘脑分泌素对基底前脑区域的输出是同侧的，而对蓝斑的输出则更多是双侧的（65%）。基底前脑突出的下丘脑神经元略微倾向于分布在下丘脑细胞组的内侧。相反，下丘脑分泌素神经元投射到蓝斑主要位于下丘脑分泌素细胞组的背侧。最后，很大比例的下丘脑分泌素神经元似乎同时投射到至少两个所检查的终端场。这些后一种观察结果表明，下丘脑泌素在多个唤醒相关区域的协调作用。(C) 2004 Wiley-Liss, Inc。
Hypocretin/orexin neurons give rise to an extensive projection system, portions of which innervate multiple regions associated with the regulation of behavioral state. These regions include the locus coeruleus, medial septal area, medial preoptic area, and substantia innominata. Evidence indicates that hypocretin modulates behavioral state via actions within each of these terminal fields. To understand better the circuitry underlying hypocretin-dependent modulation of behavioral state, the present study characterized the degree to which there exists: 1) lateralization of hypocretin efferents to basal forebrain and brainstem arousal-related regions, 2) topographic organization of basal forebrain- and brainstem-projecting hypocretin neurons, and 3) collateralization of individual hypocretin neurons to these arousal-related terminal fields. These studies utilized combined immunohistochemical identification of hypocretin neurons with single or double retrograde tracing from the locus coeruleus, medial preoptic area, medial septal area, and substantia innominata. Results indicate that approximately 80% of hypocretin efferents to basal forebrain regions project ipsilaterally, whereas projections to the locus coeruleus are more bilateral (65%). There was a slight preference for basal forebrain-projecting hypocretin neurons to be distributed within the medial half of the hypocretin cell group. In contrast, hypocretin neurons projecting to the locus coeruleus were located primarily within the dorsal half of the hypocretin cell group. Finally, a large proportion of hypocretin neurons appear to project simultaneously to at least two of the examined terminal fields. These latter observations suggest coordinated actions of hypocretin across multiple arousal-related regions. (C) 2004 Wiley-Liss, Inc.