Dinger B, Fidone S J, Stensaas F J
J Physiol. 1984 Nov;356:49-64. doi: 10.1113/jphysiol.1984.sp015452.
The proximal stump of the carotid sinus nerve (c.s.n.) branch of the IXth cranial nerve was surgically cross-anastomosed to the distal stump of the lingual nerve (l.n.) branch of the same cranial nerve to test the ability of regenerating c.s.n. axons to reinnervate and induce taste buds on cat circumvallate papillae. The l.n. branch of the IXth nerve, which normally innervates circumvallate papillae, was directed away from the tongue by suturing it to the distal stump of the c.s.n. Animals with normal and re-anastomosed (cut, then resutured) l.n. served as control preparations. 2-19 months following cross-anastomosis, circumvallate papillae contained 59.8 +/- 9.1% (mean +/- S.E. of mean) of the normal incidence of taste buds, indicating that axons possessing specific gustatory trophic properties had reinnervated the epithelium. Further experimentation was concerned with confirming the identity of the putative foreign axons which reinnervated the taste buds. Radiolabelled axoplasmic transport and autoradiography showed that 89 +/- 4.4% of the taste buds in cross-anastomosed, and 97 +/- 2.1% in normal preparations were innervated by axons from the principal sensory ganglion (petrosal) of the IXth nerve (P greater than 0.05). Whole-nerve recordings in cross-anastomosed preparations demonstrated gustatory activity in the transposed c.s.n., which was similar to responses present in normal and re-anastomosed l.n. preparations. The largest response was evoked by 4 M-NaCl, followed by 1 M-NH4Cl and 0.02 M-quinine HCl. Sucrose (0.5 M) elicited insignificant nerve activity. In normal animals, gustatory or mechanical stimulation did not alter cardiopulmonary function, but in bilaterally cross-anastomosed preparations, gustatory stimuli produced respiratory excitation while mechanical stimulation resulted in reductions in blood pressure and respiratory inhibition. These data suggest that following cross-anastomosis, arterial chemosensory axons innervate taste buds and barosensory axons innervate tongue mechanoreceptors (which normally evoke cardiopulmonary reflexes from the carotid body and carotid sinus, respectively). We conclude that arterial chemosensory neurones share with gustatory chemosensory neurones a trophic function essential for the development and maintenance of taste buds.
将第九对脑神经的颈动脉窦神经（c.s.n.）分支的近端残端与同一脑神经的舌神经（l.n.）分支的远端残端进行手术交叉吻合，以测试再生的c.s.n.轴突重新支配并诱导猫轮廓乳头味蕾的能力。第九对脑神经的l.n.分支通常支配轮廓乳头，通过将其缝合到c.s.n.的远端残端使其远离舌头。具有正常和重新吻合（切断后再缝合）的l.n.的动物作为对照制剂。交叉吻合后2至19个月，轮廓乳头含有正常味蕾发生率的59.8±9.1%（平均值±平均标准误），表明具有特定味觉营养特性的轴突已重新支配上皮。进一步的实验旨在确认重新支配味蕾的推定外来轴突的身份。放射性标记的轴浆运输和放射自显影显示，交叉吻合制剂中89±4.4%的味蕾，以及正常制剂中97±2.1%的味蕾由第九对脑神经（岩神经）的主要感觉神经节的轴突支配（P>0.05）。交叉吻合制剂中的全神经记录显示，移位的c.s.n.中有味觉活动，这与正常和重新吻合的l.n.制剂中的反应相似。最大反应由4M - NaCl引起，其次是1M - NH4Cl和0.02M - 奎宁HCl。蔗糖（0.5M）引起的神经活动不明显。在正常动物中，味觉或机械刺激不会改变心肺功能，但在双侧交叉吻合制剂中，味觉刺激会引起呼吸兴奋，而机械刺激会导致血压降低和呼吸抑制。这些数据表明，交叉吻合后，动脉化学感觉轴突支配味蕾，压力感觉轴突支配舌机械感受器（通常分别从颈动脉体和颈动脉窦引发心肺反射）。我们得出结论，动脉化学感觉神经元与味觉化学感觉神经元共享对味蕾发育和维持至关重要的营养功能。
