Fay R R, Edds-Walton P L
Parmlr Hearing Institute, Loyola University Chicago, IL 60626, USA.
Philos Trans R Soc Lond B Biol Sci. 2000 Sep 29;355(1401):1281-4. doi: 10.1098/rstb.2000.0684.
This paper reviews and discusses several investigations of the peripheral neural code for the directional axis of acoustical particle motion in the saccule of two fishes: goldfish (Carassius auratus) and toadfish (Opsanus tau). Most saccular afferents are directional in the manner of hair cells, having a cosine-shaped directional response pattern. The saccular sensory epithelia are orientated almost vertically in a parasagittal plane. In the horizontal plane, these epithelia are orientated obliquely with respect to the midline. Hair-cell stereocilia project perpendicularly. Thus, directional response patterns of saccular afferents tend to be orientated in azimuth parallel to the orientation of the epithelia in the head. The oblique angle of the toadfish saccule is greater than that of the goldfish, and the range of best directions in the horizontal plane for each species reflects those differing orientations. The azimuth of acoustical particle motion could be computed by comparing the relative activation of the two saccules, as is the case for the ears of most terrestrial vertebrates. The spatial patterns of saccular hair-cell orientation of most fishes thus appear to have little function in azimuthal source location, but for toadfish are probably most important for determining the elevation of monopole sources.
本文回顾并讨论了对两种鱼类（金鱼（Carassius auratus）和蟾鱼（Opsanus tau））球囊内声学粒子运动方向轴的外周神经编码的几项研究。大多数球囊传入神经以毛细胞的方式具有方向性，呈现余弦形的方向响应模式。球囊感觉上皮几乎垂直地排列在矢状旁平面内。在水平面内，这些上皮相对于中线倾斜排列。毛细胞静纤毛垂直伸出。因此，球囊传入神经的方向响应模式倾向于在方位上与头部上皮的方向平行排列。蟾鱼球囊的倾斜角度大于金鱼的，每个物种在水平面内的最佳方向范围反映了这些不同的排列方式。声学粒子运动的方位可以通过比较两个球囊的相对激活来计算，就像大多数陆生脊椎动物的耳朵那样。因此，大多数鱼类球囊毛细胞的空间排列模式在方位声源定位中似乎作用不大，但对于蟾鱼来说，可能对于确定单极声源的仰角最为重要。
