Puzdrowski R L
J Comp Neurol. 1987 May 15;259(3):382-92. doi: 10.1002/cne.902590306.
Taste buds in goldfish and other cyprinids are found not only within the oropharyngeal cavity but also scattered over the external body surface. The external taste buds are innervated by branches of the facial nerve that terminate centrally in an enlargement of the medulla termed the facial lobe. The peripheral distribution and areas of innervation of the rami of the facial sensory nerve were determined by using a modification of the Sihler technique and by examination of a Bodian-stained head series. The central projections of individual rami of the facial sensory nerve were traced by means of the horseradish peroxidase (HRP) technique. Fibers of the facial sensory nerve distribute over the head and trunk via nine rami. The supraorbital ramus distributes fibers to taste buds above the eye. The palatine, maxillary, and mandibular rami innervate taste buds of the rostral palate, upper lip, and lower lip, respectively. The three rami of the hyomandibular trunk innervate taste buds on the operculum, branchiostegal rays, and in the lower cheek region. A facial recurrent ramus was also found that distributes fibers to taste buds on the trunk and pectoral fin via two rami, the lateral recurrent ramus and pectoral recurrent ramus. The facial sensory rami map somatotopically on the facial lobe. Overall, the projections follow an anteroposterior orientation with the long axis of the body tilted slightly ventrally. The lips and rostral palate make up a disproportionately large portion of the map, taking up nearly the entire ventral extent of the lobe. The trunk and pectoral fin regions map broadly across the dorsal portion of the lobe. Further, projections to the nucleus of the descending trigeminal tract were observed with labeling of the supraorbital, maxillary, and mandibular rami, and the rami of the hyomandibular trunk. Projections to the facial motor nucleus were also observed with labeling of maxillary and mandibular rami, perhaps indicating a monosynaptic reflex are. These projections have not been reported in previous studies on the teleostean facial taste system.
金鱼和其他鲤科鱼类的味蕾不仅存在于口咽腔内，还散布于体表。外部味蕾由面神经分支支配，这些分支在延髓的一个扩大区域（称为面神经叶）内终止于中枢。通过对西勒技术的改进以及对博迪安染色的头部系列进行检查，确定了面神经感觉支的外周分布和神经支配区域。借助辣根过氧化物酶（HRP）技术追踪了面神经感觉支各分支的中枢投射。面神经感觉神经纤维通过九个分支分布于头部和躯干。眶上支将纤维分布到眼上方的味蕾。腭支、上颌支和下颌支分别支配吻部腭部、上唇和下唇的味蕾。舌颌干的三个分支支配鳃盖、鳃条骨以及下颊区域的味蕾。还发现了一条面神经返支，它通过外侧返支和胸鳍返支这两个分支将纤维分布到躯干和胸鳍的味蕾。面神经感觉支在面神经叶上呈躯体定位分布。总体而言，投射沿着前后方向，身体的长轴略微向腹侧倾斜。嘴唇和吻部腭部在图谱中占比过大，几乎占据了叶的整个腹侧范围。躯干和胸鳍区域广泛分布在叶的背侧部分。此外，在眶上支、上颌支、下颌支以及舌颌干的分支标记中观察到了向下三叉神经核的投射。在上颌支和下颌支标记中也观察到了对面神经运动核的投射，这可能表明存在单突触反射弧。这些投射在先前关于硬骨鱼类面神经味觉系统的研究中尚未有报道。
