Maruska Karen P, Tricas Timothy C
Department of Zoology, University of Hawai'i at Manoa, Honolulu, Hawai'i 96822, USA.
J Comp Neurol. 2009 Feb 10;512(5):628-50. doi: 10.1002/cne.21923.
Sounds and hydrodynamic stimuli are important cues detected by the octavolateralis system in fishes. The central organization of auditory, mechanosensory, and vestibular projections is known for only a few phylogenetically diverse fishes, and less is known about projections in derived perciforms that use sounds for acoustic communication. We used neuronal labeling to provide a detailed analysis of octavolateralis endorgan projections in a soniferous perciform that does not have accessory morphological structures to enhance hearing. Octavolateralis nerves terminate ipsilaterally within seven medullary octaval nuclei: caudal (CON) and medial (MON) octavolateralis, anterior (AON), descending (DON), magnocellular (MgON), tangential (TON), and posterior (PON) octaval nuclei, and the eminentia granularis (EG). Anterior and posterior lateral line nerves project to the CON and MON, with dense projections to the EG. Semicircular canal nerves project primarily to ventral regions including the TON, ventral DON, intermediate DON (DONi), and MgON. Otolithic, semicircular canal, and anterior lateral line nerves all project to the MgON, which may serve a sensorimotor integration function. The DONi receives primarily segregated projections from all otolithic and semicircular canal nerves, whereas the ventral DON and TON receive principally utricular and semicircular canal afferents. The AON receives dense lateral and ventral projections from the saccule and utricle, and medial and dorsal projections from the lagena. These projection patterns are similar to those reported for non-sonic perciforms, and indicate the absence of neuroanatomical modifications in first-order octavolateralis nuclei in species that use acoustic communication. Thus patterns of central projections may be conserved among vocal and non-vocal perciforms.
声音和流体动力刺激是鱼类八侧线系统检测到的重要线索。仅对少数系统发育上不同的鱼类了解听觉、机械感觉和前庭投射的中枢组织，而对于利用声音进行声学交流的衍生鲈形目鱼类的投射了解较少。我们使用神经元标记对一种没有辅助形态结构来增强听力的发声鲈形目鱼类的八侧线终器投射进行了详细分析。八侧线神经在同侧终止于七个延髓八面体核：尾侧（CON）和内侧（MON）八侧线核、前侧（AON）、下行（DON）、大细胞（MgON）、切线（TON）和后侧（PON）八面体核，以及颗粒隆起（EG）。前侧和后侧侧线神经投射到CON和MON，密集投射到EG。半规管神经主要投射到包括TON、腹侧DON、中间DON（DONi）和MgON在内的腹侧区域。耳石、半规管和前侧侧线神经都投射到MgON，MgON可能具有感觉运动整合功能。DONi主要接收来自所有耳石和半规管神经的分离投射，而腹侧DON和TON主要接收椭圆囊和半规管传入纤维。AON接收来自球囊和椭圆囊的密集外侧和腹侧投射，以及来自瓶状囊的内侧和背侧投射。这些投射模式与报道的非发声鲈形目鱼类的模式相似，表明在使用声学交流的物种中，一级八侧线核中不存在神经解剖学改变。因此，中枢投射模式在发声和非发声鲈形目鱼类中可能是保守的。
