Chien C H, Shieh J Y, Ling E A, Tan C K, Wen C Y
Department of Anatomy, College of Medicine, National Taiwan University, Taipei, Taiwan.
J Anat. 1996 Oct;189 ( Pt 2)(Pt 2):349-62.
The cranial components and central terminations of the sensory nerves supplying the concave surface of the puppy's pinna, namely, the rostral, middle and caudal internal auricular nerves (RIAN, MIAN and CIAN) were investigated using horseradish peroxidase retrograde and transganglionic labelling techniques. All the 3 internal auricular nerves received contributions from the vagus. The RIAN received additional fibres from the trigeminal nerve while the MIAN and CIAN contained fibres derived from the facial nerves. In the brainstem, collaterals from the descending fibres of the afferents were given off at all levels to the medially located spinal trigeminal nucleus (SpV) which extended rostocaudally from the principal nucleus of the trigeminal nerve, subnuclei oralis, interpolaris and caudalis of the SpV to C1 or C2 cervical segment. The greatest density of central projections was observed in the subnucleus caudalis and C1. In the latter, the terminal field in the dorsal horn was roughly wedge-shaped, tapering off medially from lamina I towards lamina V. A somatotopic organisation was observed in the spinal trigeminal tract (SpVtr) and spinal trigeminal nucleus (SpV) in which the projection fibres and terminal fields of the RIAN were located lateral to those of the MIAN and CIAN. Some nontrigeminal nuclei, e.g. paratrigeminal and cuneate nuclei, nucleus X and the nucleus of the solitary tract were also labelled following HRP application to the internal auricular nerves. The localisation of the central projections of the internal auricular nerves as well as the 2nd order neurons in some specific nuclei to which the afferent fibres project is consistent with the concept of a brainstem somatovisceral link.
采用辣根过氧化物酶逆行和顺行跨节标记技术，研究了支配幼犬耳廓凹面的感觉神经的颅部成分及中枢终末，即耳内前、中、后神经（RIAN、MIAN和CIAN）。所有3条耳内神经均接受迷走神经的分支。RIAN还接受三叉神经的额外纤维，而MIAN和CIAN含有来自面神经的纤维。在脑干，传入纤维的下行纤维在各级均发出侧支至内侧的三叉神经脊束核（SpV），该核从三叉神经主核、SpV的口侧亚核、极间亚核和尾侧亚核一直延伸至颈1或颈2节段。在尾侧亚核和颈1节段观察到中枢投射的最大密度。在颈1节段，背角的终末野大致呈楔形，从板层Ⅰ向内侧逐渐变细至板层Ⅴ。在三叉神经脊束（SpVtr）和三叉神经脊束核（SpV）中观察到了躯体定位组织，其中RIAN的投射纤维和终末野位于MIAN和CIAN的外侧。在将HRP应用于耳内神经后，一些非三叉神经核，如三叉旁核和楔束核、迷走神经背核和孤束核也被标记。耳内神经中枢投射的定位以及传入纤维投射到的一些特定核团中的二级神经元与脑干躯体-内脏联系的概念一致。
