Yoshida A, Chen K, Moritani M, Yabuta N H, Nagase Y, Takemura M, Shigenaga Y
Department of Oral Anatomy, Osaka University Faculty of Dentistry, Suita, Japan.
J Comp Neurol. 1997 Jun 23;383(1):94-111.
To clarify direct descending projections from the parabrachial nucleus (PB) to the trigeminal sensory nuclear complex (TSNC) and spinal dorsal horn (SpDH), the origin and termination of descending tract cells were examined by the anterograde and retrograde transport methods. Phaseolus vulgaris leucoagglutinin (PHA-L) and Fluorogold (FG) or dextran-tetramethylrhodamine (Rho) were used as neuronal tracers for the anterograde and retrograde transport, respectively. The ventrolateral PB, including Kölliker-Fuse nucleus (KF), sent axons terminating mainly in the ventrolateral parts of rostral trigeminal nuclei of the principalis (Vp), oralis (Vo), and interpolaris (Vi) as well as in the inner lamina II of the medullary (nucleus caudalis, Vc) and SpDH. Although the descending projections were bilateral with an ipsilateral dominance, TSNC received a more dominant ipsilateral projection than SpDH. The cells of origin of the descending tracts were located mainly in KF, but TSNC received fewer projections from the KF than SpDH. Namely, TSNC received a considerable projection from the medial subnucleus of PB and the ventral parts of lateral subnuclei of PB, such as the central lateral subnucleus and lateral crescent area. The other difference noted between TSNC and SpDH was that the former received projections mainly from the caudal two thirds of KF and the latter from the rostral two thirds of KF. These results demonstrate the existence of direct parabrachial projections to TSNC and SpDH that are organized in a distinct manner and suggest that both pathways are involved in the control of nociception.
为明确臂旁核（PB）至三叉神经感觉核复合体（TSNC）和脊髓背角（SpDH）的直接下行投射，采用顺行和逆行运输法研究了下行传导束细胞的起源和终末。分别使用菜豆白细胞凝集素（PHA-L）和顺行运输的神经元示踪剂，以及荧光金（FG）或葡聚糖四甲基罗丹明（Rho）作为逆行运输的神经元示踪剂。包括 Kölliker-Fuse 核（KF）在内的腹外侧 PB 发出的轴突主要终止于三叉神经主核（Vp）、口核（Vo）和极间核（Vi）的吻侧三叉神经核的腹外侧部分，以及延髓（尾侧亚核，Vc）和 SpDH 的内板层 II。尽管下行投射是双侧的，以同侧为主，但 TSNC 比 SpDH 接受更占优势的同侧投射。下行传导束的起源细胞主要位于 KF，但 TSNC 比 SpDH 从 KF 接受的投射更少。也就是说，TSNC 从 PB 的内侧亚核和 PB 外侧亚核的腹侧部分，如中央外侧亚核和外侧新月区，接受相当多的投射。TSNC 和 SpDH 之间的另一个区别是，前者主要从 KF 的尾侧三分之二接受投射，而后者从 KF 的吻侧三分之二接受投射。这些结果表明存在至 TSNC 和 SpDH 的直接臂旁投射，且它们以独特的方式组织，并提示这两条通路均参与伤害性感受的控制。
