大鼠大脑皮质─蓝斑─小脑通路──HRP溃变电镜研究

The pathway of the cortico-locus ceruleus-cerebellum in rats: An electron microscopic study using the horseradish peroxidase tracing combined with degeneration method

目的为了在超微水平上证实发质-LC-小脑通路的存在。方法采用顺行溃变与HRP逆行示踪相结合电镜技术。结果在LC颅测部观察到中（d＜2μm）、小（d＜1μm）型溃变前囊，以电子致密型为主，偶见神经微丝型溃变。电子致密型演变前囊中的小泡以圆形清亮小泡为主，偶见大颗粒小泡和扁平小泡。同时在LC的颅测部观察到大量HRP逆标神经元胞体和树突。部分溃变前囊与HRP逆标神经元形成非对称型轴-树突触。部分溃变的前囊与非HRP标记树突形成轴-树突触。结论皮质-LC投射和LC-小脑投射在LC内存在单突触连接；皮质纤维不仅投向LC内的小脑投射神经元，也投向LC内其它神经元。

Objective The synaptic relahonships between the axon terminals from cerebral cortex and the LC neu rons were studied electron microscopically.Methods The horseradish peroxidase (HRP) tracing combined with degenera tion method was used to demonstrate the pathway of the cortico-locus ceruleus(LC)-cerebellum in rat. Results Degenerat ed axon terminals were seen in the cranial part of LC,most of which belong to electron dense degeneration,while a few of them filamentous degeneration. HRP labelled neurons were seen in LC.Some of the degenerated terminals formed synapses with HRP labelled neurons in LC. Some degenerated axon terminals formed axodendritic synapses with non labelled dendri ties(Gray Ⅰ type and Ⅱ type). Conclusion This study demonstrated ultrastructurally the existing of cortico LC cerebellum pathway, and provided the morphological evidence for the transmission and integration function of LC.