Dovas A, Lucchi M L, Bortolami R, Grandis A, Palladino A R, Banelli E, Carretta M, Magni F, Paolocci N
Istituto di Patologia Generale, Cattedra di Fisiologia Umana, Facoltà di Medicina e Chirurgia, Università di Perugia, Italy.
Brain Res. 1998 Nov 2;809(2):141-8. doi: 10.1016/s0006-8993(98)00705-7.
The origin and course of efferent vagal fibers, which innervate the rat thymus, were investigated by a fluorescent retrograde double labeling method, using Fast blue (FB) and Diamidino yellow dihydrochloride (DY) as tracers. In the same animal, one tracer was injected into the cranial portion of the right lobe of the thymus and the other dye was deposited around the cut end of the right recurrent laryngeal nerve. The neuronal population giving origin to the recurrent nerve was mapped by using retrograde labeling with HRP applied to the central stump of the nerve. The HRP retrograde axonal transport showed that most efferent vagal fibers of the recurrent nerve have their perikarya in the nucleus retroambigualis (NRA), nucleus ambiguus (NA), and to a lesser extent in the nucleus retrofacialis (NRF). In fluorescent retrograde double labeling of thymus and recurrent laryngeal nerve both single and double labeled cells were found. The cells labeled by the injections into the thymus were colocalized with the neurons labeled by the tracer deposited in the recurrent laryngeal nerve to the NRA, NA, and NRF. Moreover along the rostrocaudal extent of the NRF and NA double labeled cells were present, showing that some of the thymic efferents are collaterals of the recurrent nerve fibers. Our experiments shown that some thymic vagal fibres originate from neurons of nucleus dorsalis nervi vagi (NDV) as demonstrated both by HRP and FB injected thymuses. The possible role of these efferents in thymic function is briefly discussed.
采用荧光逆行双重标记法，以快蓝（FB）和二盐酸双脒基黄（DY）作为示踪剂，研究了支配大鼠胸腺的迷走神经传出纤维的起源和行程。在同一只动物中，将一种示踪剂注入胸腺右叶的头端部分，另一种染料沉积在右喉返神经的切断端周围。通过将辣根过氧化物酶（HRP）逆行标记应用于神经的中枢残端，绘制了发出喉返神经的神经元群。HRP逆行轴突运输显示，喉返神经的大多数迷走神经传出纤维的胞体位于疑后核（NRA）、疑核（NA），少数位于面神经后核（NRF）。在胸腺和喉返神经的荧光逆行双重标记中，发现了单标记和双标记细胞。注入胸腺的标记细胞与沉积在喉返神经中的示踪剂标记至NRA、NA和NRF的神经元共定位。此外，沿NRF和NA的 rostrocaudal 范围存在双标记细胞，表明一些胸腺传出纤维是喉返神经纤维的侧支。我们的实验表明，一些胸腺迷走纤维起源于迷走神经背核（NDV）的神经元，HRP和FB注入胸腺均证实了这一点。简要讨论了这些传出纤维在胸腺功能中的可能作用。
