Casseday J H, Covey E, Vater M
Department of Surgery (Otolaryngology), Duke University Medical Center, Durham 27710.
J Comp Neurol. 1988 Dec 15;278(3):313-29. doi: 10.1002/cne.902780302.
In the rufous horseshoe bat (Rhinolophus rouxi), the superior olivary complex contains four main divisions. In comparison with other species, the most lateral division is clearly homologous to the lateral superior olive (LSO); the most medial division is homologous to the medial nucleus of the trapezoid body (MNTB). Lying between these landmarks, in approximately the position of the medial superior olive (MSO) of other mammals, are two additional divisions that are cytoarchitecturally distinct from one another yet do not greatly resemble the MSO of nonecholocating mammals such as the cat. We refer to these nuclei as the dorsal medial superior olive (DMSO) and the ventral medial superior olive (VMSO). We examined the afferent and efferent connections of all of these cell groups with retrograde and anterograde transport of WGA-HRP from the superior olivary complex. In the same animals we recorded the binaural response properties of single units in the superior olivary complex. Virtually all units recorded in LSO were excitatory to the ipsilateral ear and inhibitory to the contralateral ear (EI); all of the units sampled in the MNTB and most of those sampled in the VMSO responded only to the contralateral ear (OE). In DMSO the binaural properties of units were varied: the number of units that were inhibitory to the ipsilateral ear and excitatory to the contralateral ear (IE) was about equal to the number of units excitatory to both ears (EE); a few units had OE responses; no units had EI responses. Connectional correlates for these binaural response properties are seen in the patterns of retrograde transport from WGA-HRP injections in the divisions of the superior olive. The LSO receives projections from the ipsilateral cochlear nucleus and MNTB; MNTB receives projections from the contralateral cochlear nucleus. The DMSO and VMSO both receive bilateral projections from the cochlear nuclei. The results of retrograde and anterograde transport suggest that VMSO, in addition, receives projections from the ipsilateral MNTB. The LSO, DMSO, and VMSO all project to the ventral two-thirds of the central nucleus of the inferior colliculus, and their targets are approximately coextensive. However, the LSO projects bilaterally to the inferior colliculus, whereas the medial cell groups project mainly ipsilaterally.
在棕果蝠（Rhinolophus rouxi）中，上橄榄复合体包含四个主要部分。与其他物种相比，最外侧的部分明显与外侧上橄榄核（LSO）同源；最内侧的部分与梯形体内侧核（MNTB）同源。在这两个标志性结构之间，大致处于其他哺乳动物内侧上橄榄核（MSO）的位置，还有另外两个部分，它们在细胞结构上彼此不同，但与猫等非回声定位哺乳动物的MSO不太相似。我们将这些核称为背内侧上橄榄核（DMSO）和腹内侧上橄榄核（VMSO）。我们通过从上橄榄复合体逆行和顺行运输WGA-HRP来研究所有这些细胞群的传入和传出连接。在同一批动物中，我们记录了上橄榄复合体内单个神经元的双耳反应特性。几乎所有在LSO记录到的神经元对同侧耳兴奋，对侧耳抑制（EI）；在MNTB中采样的所有神经元以及在VMSO中采样的大多数神经元仅对侧耳有反应（OE）。在DMSO中，神经元的双耳特性各不相同：对同侧耳抑制、对侧耳兴奋的神经元（IE）数量与对双耳都兴奋的神经元（EE）数量大致相等；少数神经元有OE反应；没有神经元有EI反应。这些双耳反应特性的连接相关在从上橄榄核各部分注射WGA-HRP的逆行运输模式中可见。LSO接受来自同侧耳蜗核和MNTB的投射；MNTB接受来自对侧耳蜗核的投射。DMSO和VMSO都接受来自耳蜗核的双侧投射。逆行和顺行运输的结果表明，此外，VMSO还接受来自同侧MNTB的投射。LSO、DMSO和VMSO都投射到下丘中央核的腹侧三分之二，它们的靶区大致重叠。然而，LSO双侧投射到下丘，而内侧细胞群主要同侧投射。
