Limited convergence of rhinal cortical and dopaminergic inputs in the rat basolateral amygdala: an ultrastructural analysis.
Limited convergence of rhinal cortical and dopaminergic inputs in the rat basolateral amygdala: an ultrastructural analysis.
复制标题
大鼠基底外侧杏仁核鼻皮质和多巴胺能输入的有限收敛：超微结构分析。
DOI：
10.1016/j.brainres.2010.03.062
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发表时间：
2010
期刊：
影响因子：
2.9
通讯作者：
McDonald,AlexanderJ
中科院分区：
文献类型：
--
作者：
Pinard,CourtneyR;Mascagni,Franco;Muller,JayF;McDonald,AlexanderJ
杏仁核基底外侧复合体（BLC）接收来自鼻皮质（RCx）的强烈感觉输入，这对情绪行为的产生很重要。BLC也是中脑边缘多巴胺（DA）系统的主要靶点之一。DA增强BLC的皮层感觉输入，这导致BLC锥体细胞的兴奋性增加。这些结果表明，可能有收敛的RCx和DA输入到树突的锥体细胞的BLC。在本研究中，我们使用双标记免疫组织化学和顺行追踪的超微结构水平，以测试这一假设在大鼠脑。RCx轴突标记菜豆白细胞凝集素（PHA-L）注射，而酪氨酸羟化酶（TH）被用作DA轴突的标记。在基底外侧核（BLp）的后分部，这是密集的神经支配的两个输入，这些轴突的会聚程度进行了分析。RCx突触不对称，主要接触树突棘（86.4%）和树突干（12.1%）。TH阳性终末也主要与树突的棘和轴形成对称性突触和并置。然而，超微结构分析发现，与DA终末会聚到未标记的树突（9.4%）和轴突（7.5%），或表现出与TH+终末直接接触（3.8%）的RCx终末的百分比非常低。这些研究结果表明，特定的行为显着的感觉刺激与多巴胺释放的BLC的关联是不依赖于一个点到点的空间关系的皮质和DA输入。
The basolateral nuclear complex of the amygdala (BLC) receives robust sensory inputs from the rhinal cortices (RCx) that are important for the generation of emotional behavior. The BLC is also one of the main targets of the mesolimbic dopamine (DA) system. DA potentiates cortical sensory inputs to the BLC, which leads to an increase in the excitability of BLC pyramidal cells. These findings suggest that there may be convergence of RCx and DA inputs onto the dendrites of pyramidal cells in the BLC. In the present study we used dual-labeling immunohistochemistry and anterograde tract-tracing at the ultrastructural level to test this hypothesis in the rat brain. RCx axons were labeled by Phaseolus vulgaris leucoagglutinin (PHA-L) injections, whereas tyrosine hydroxylase (TH) was used as a marker for DA axons. The extent of convergence of these axons was analyzed in the posterior subdivision of the basolateral nucleus (BLp), which is densely innervated by both inputs. RCx synapses were asymmetrical and mainly contacted dendritic spines (86.4%) and dendritic shafts (12.1%). TH-positive (TH+) terminals also mainly formed synapses (symmetrical) and appositions with spines and shafts of dendrites. However, ultrastructural analysis found a very low percentage of RCx terminals converging with DA terminals onto unlabeled dendrites (9.4%) and axons (7.5 %), or exhibiting direct contacts with TH+ terminals (3.8%). These findings suggest that the association of specific behaviorally salient sensory stimuli with dopamine release in the BLC is not dependent on a point-to-point spatial relationship of cortical and DA inputs.