ORGANIZATION OF LATERAL GENICULATE-HYPOTHALAMIC CONNECTIONS IN THE RAT
ORGANIZATION OF LATERAL GENICULATE-HYPOTHALAMIC CONNECTIONS IN THE RAT
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DOI：
10.1002/cne.902840110
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发表时间：
1989-06-01
影响因子：
2.5
通讯作者：
MOORE, RY
中科院分区：
文献类型：
--
作者：
CARD, JP;MOORE, RY
的位置和化学身份的神经元相互连接的外侧膝状体复合体和下丘脑进行了分析，以提供进一步的信息，夹带的昼夜节律的解剖基板。本研究的一个特殊目的是描述外侧膝状体复合体的膝状体间叶（IGL）和视交叉上核（SCN）及相关下丘脑前部区域之间投射的神经元。连接实验采用五种组合的荧光示踪剂注射，并结合免疫组织化学定位的神经肽Y（NPY），甲硫氨酸脑啡肽（mENK）或血管活性肠多肽（VIP）/肽组氨酸异亮氨酸（PHI）组。IGL传出神经。注射示踪剂到SCN的结果在逆行标记的神经肽Y免疫反应神经元的IGL将预期从先前的工作。这些神经元及其末梢还含有NPY前体分子（CPON）的C-侧翼肽。此外，IGL中还有两组神经元投射到SCN或对侧IGL，但不表现出NPY免疫反应性。这些包括大量的细胞，项目的SCN和更大的一组神经元，项目对侧IGL和含有mENK免疫反应。下丘脑传出神经。将示踪剂注射到IGL中会导致在整个SCN和紧邻同侧下丘脑前部的分散神经元的逆行标记，并且还导致在大脑对侧的相同区域中的少量神经元的标记。在极少数情况下，个别SCN神经元似乎投射到两个IGL。然而，视交叉后区（RCA）含有最大数量的逆行标记的神经元后，示踪剂注射到IGL。这些神经元集中在沿着正中矢状面和注射IGL同侧的外侧RCA中。SCN或邻近下丘脑前部的标记神经元均未显示VIP或PHI免疫反应性。这些观察结果表明，膝状体复合体和下丘脑前部之间的解剖关系比以前所示的更为复杂。首先，膝状体下丘脑束来自两个不同的IGL神经元组：一个包含NPY/CPON免疫反应性;其他的化学成分是不是在目前的时间特点。第二，两个IGL之间的连合投射由第三组神经元形成，这些细胞含有mENK免疫反应性。最后，从下丘脑到IGL的相互投射来自视交叉后区、SCN和邻近的下丘脑前部的神经元。这些解剖学观察表明，参与昼夜节律夹带的神经元回路由一系列复杂的预测，互连SCN，下丘脑前部和IGL。
The location and chemical identity of neurons interconnecting the lateral geniculate complex and the hypothalamus were analyzed in order to provide further information on the anatomical substrates for the entrainment of circadian rhythms. A particular objective of the study was to characterize the neurons projecting between the intergeniculate leaflet (IGL) of the lateral geniculate complex and the suprachiasmatic nucleus (SCN) and related anterior hypothalamic areas. The connectivity experiments employed five combinations of fluorescent tracer injection and were combined with immunohistochemical localization of either neuropeptide Y (NPY), met-enkephalin (mENK) or the vasoactive intestinal polypeptide (VIP)/peptide histidine isoleucine (PHI) group. IGL efferents. Injection of tracer into the SCN results in retrograde labeling of NPY-immunoreactive neurons in the IGL as would be expected from prior work. These neurons and their terminals also contain the C-flanking peptide of the NPY precursor molecule (CPON). In addition, there are two additional groups of neurons in the IGL that project either to the SCN or the contralateral IGL but do not exhibit NPY immunoreactivity. These include a substantial population of cells that project to the SCN and an even larger group of neurons which project to the contralateral IGL and contain mENK immunoreactivity. Hypothalamic efferents. Injection of tracer into the IGL results in retrograde labeling of scattered neurons throughout the SCN and immediately adjacent anterior hypothalamus ipsilaterally and also in labeling of a small number of neurons in the same areas on the contralateral side of the brain. In rare instances, individual SCN neurons appear to project to both IGLs. However, the retrochiasmatic area (RCA) contains the largest number of retrogradely labeled neurons following tracer injections into the IGL. These neurons are concentrated along the midsagittal plane and in the lateral RCA ipsilateral to the injected IGL. None of the labeled neurons in the SCN or adjacent anterior hypothalamus exhibit VIP or PHI immunoreactivity. These observations indicate that the anatomical relations between the geniculate complex and the anterior hypothalamus are more complex than previously shown. First, the geniculohypothalamic tract arises from two distinct groups of IGL neurons: one contains NPY/CPON immunoreactivity; the chemical content of the other is not characterized at the present time. Second, the commissural projection between the two IGLs is formed by a third group of neurons, and these cells contain mENK immunoreactivity. Finally, reciprocal projections from the hypothalamus to the IGL arise from neurons in the retrochiasmatic area, SCN, and adjacent anterior hypothalamus. These anatomical observations demonstrate that the neuronal circuitry involved in the entrainment of circadian rhythms consists of a complex series of projections that interconnect the SCN, anterior hypothalamus, and IGL.