Afferent connections of anterior thalamus in rats: sources and association with muscarinic acetylcholine receptors.
Afferent connections of anterior thalamus in rats: sources and association with muscarinic acetylcholine receptors.
复制标题
大鼠前丘脑的传入连接：来源及其与毒蕈碱乙酰胆碱受体的关联。
DOI：
10.1002/cne.902560406
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Vogt,BA
中科院分区：
文献类型：
--
作者：
Sikes,RW;Vogt,BA
丘脑前核（ATN）的传入联系被经典地认为起源于乳头体和边缘皮质。本研究探讨非边缘来源的ATN传入使用辣根过氧化物酶（HUP）的逆行运输，以确定这些连接的相对贡献。HRP扩散到邻近区域被阻止通过去除覆盖皮层或通过永久植入cannulas.The主要来源的非边缘ATN传入的前顶盖和中央灰质注射。顶盖前神经元主要在对侧顶盖前内侧核中被HRP标记，在同侧顶盖前后核中的标记数量较少。在中央灰质，标记细胞集中在同侧的背外侧被盖核。在正常大鼠和毁损大鼠中，用毒蕈碱配体丙基苄胆碱氮芥（PrCl 4）和哌仑西平（PZ）进行受体放射自显影，研究了ATN传入与毒蕈碱受体的联系。将鹅膏蕈氨酸注射到ATN中用于破坏内在神经元，同时保持传入纤维完整。尽管这种消融导致前背核（AD，−45%）和前腹核大细胞部分（AVm，−51%）中Pre结合的统计学显著降低，但前腹核小细胞部分（AVp）和前内侧核（AM）中的结合并未显著降低。此外，正常大鼠ATN中的PZ结合显著低于Pre结合（-72%）。这些结果表明，一个主要比例的毒蕈碱结合与突触前的元素。鹅膏蕈氨酸消融乳头体减少Pre结合ATN，而在扣带皮层和laterodorthoral被盖核病变没有影响。与假损伤对照组相比，乳头体损伤导致AD（−15%）、AVm（−19%）和AM（−20%）双侧结合的统计学显著性降低。在这些输入中，前顶盖可能是感觉信息到达ATN的主要途径。此外，胆碱能输入可能通过突触前毒蕈碱受体调节从乳头体到ATN的投射活动。
Afferent connections of the anterior thalamic nuclei (ATN) are classically thought to originate in the mammillary body and limbic cortex. This study explores nonlimbic sources of ATN afferents by using retrograde transport of horseradish peroxidase (HUP) to ascertain the relative contribution of these connections. Spread of HRP into adjacent regions was prevented either by removing the overlying cortex or by injecting through permanently implanted cannulas.The main sources of nonlimbic ATN afferents are the pretectum and central gray. Pretectal neurons were HRP‐labeled primarily in the contralateral medial pretectal nucleus with a smaller number in the ipsilateral posterior pretectal nucleus. In the central gray, labeled cells were concentrated ipsilaterally in the laterodorsal tegmental nucleus. Additional projections to ATN originate in the reticular and ventral lateral geniculate nuclei of the thalamus, raphe nuclei, peripontine tegmental nucleus, and locus coeruleus.The association of ATN afferents with muscarinic receptors was also explored by means ofin vitroreceptor autoradiography with the muscarinic ligands propylbenzilylcholine mustard (PrBCM) and pirenzepine (PZ) in normal rats and rats with ablations. Ibotenic acid injections into ATN were used to destroy intrinsic neurons while leaving afferent fibers intact. Whereas such ablations produced statistically significant decreases in PrBCM binding in the anterior dorsal (AD, −45%) and anterior ventral, magnocellular part (AVm, −51%) nuclei, binding in the anterior ventral, parvicellular part (AVp) and anterior medial (AM) nuclei was not significantly decreased. Furthermore, PZ binding in normal rat ATN was significantly less (−72%) than PrBCM binding. These results suggest that a major proportion of muscarinic binding is associated with presynaptic elements.Ibotenic acid ablations of the mammillary body reduced PrBCM binding in ATN whereas lesions in cingulate cortex and laterodorsal tegmental nucleus had no effect. Compared to sham lesion controls, mammillary body lesions resulted in statistically significant decreases in binding bilaterally in AD (−15%), AVm (−19%), and AM (−20%).In conclusion, ATN receive afferents from several nonlimbic regions. Of these inputs, the pretectum may be the primary route through which sensory information reaches ATN. In addition, cholinergic input may modulate activity in projections from the mammillary body to ATN through presynaptic muscarinic receptors.