FUNCTIONAL-ORGANIZATION OF MUSTACHED BAT INFERIOR COLLICULUS .2. CONNECTIONS OF THE FM2 REGION
FUNCTIONAL-ORGANIZATION OF MUSTACHED BAT INFERIOR COLLICULUS .2. CONNECTIONS OF THE FM2 REGION
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DOI：
10.1002/cne.902840107
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发表时间：
1989-06-01
影响因子：
2.5
通讯作者：
ZETTEL, ML
中科院分区：
文献类型：
--
作者：
FRISINA, RD;ONEILL, WE;ZETTEL, ML
回声定位蝙蝠通过分析它们发出的超声波的频率调制部分和由此产生的回声之间的时间延迟来估计目标距离。在同伴论文中，我们研究了在下丘中央核中，小胡子蝙蝠生物声纳信号的主要二次谐波调频分量（FM2）的表示（O' Neill等人：J. Comp. Neurol. 283:000-000, 89）。在本文中，我们报告了这部分丘的连接，通过局灶性的HRP离子电泳注射来确定FM2表示的单单位映射。下丘FM2区的主要输入信号来自对侧耳蜗核；同侧来自中上橄榄核、橄榄周核、外侧扁豆腹核和中间核；两侧的橄榄上外侧核和外侧小扁豆背核。这项研究首次确定了脑干核的特定区域，这些区域向处理小胡子蝙蝠FM2信息的下丘中央核提供输入。FM2区域的主要输出投射到内侧膝状体的内侧和背部。与其他哺乳动物形成鲜明对比的是，我们几乎没有发现与内侧膝状突起腹侧部有联系的证据。其他接收来自FM2区域的重要输入的区域包括同侧的深上丘和同侧的桥侧核。一些纤维也终止于中脑背侧导水管周围灰质中线附近。同侧中央核的背后分裂和对侧下丘在与前外侧分裂的注射部位相同的位置也可见稀疏的固有连接。FM2向内侧胫状体的投射严重倾向于内侧和背侧分裂，这一发现与Olsen （The Pteronotus parnellii of The髯蝠内侧胫状体的生物声纳信息处理）发现的“FM-FM”延迟依赖性促进神经元的位置一致。博士论文，华盛顿大学，圣路易斯，86)在这些部门，并与丘脑皮质投影模式在这个物种。这些发现表明，对于生物声呐信号的调频部分，在下丘输出水平上发生了从tonotopic处理形式到更专业、更收敛的组织模式的转变。
Echolocating bats estimate target distance by analyzing the time delay between frequency-modulated portions of their emitted ultrasonic vocalizations and the resultant echoes. In the companion paper we investigated, in the central nucleus of the inferior colliculus, the representation of the predominant second-harmonic frequency-modulated component (FM2) of the mustached bat biosonar signal (O''Neill et al.: J. Comp. Neurol. 283:000-000, ''89). In the present paper we report the connections of this part of the colliculus, as determined by focal, iontophoretic injections of HRP following single-unit mapping of the FM2 representation. It was found that the major inputs to the FM2 region of the inferior colliculus come from the contralateral cochlear nucleus; ipsilaterally from the media superior olive, periolivary nuclei, and ventral and intermediate nuclei of the lateral lemniscus; and bilaterally from the lateral superior olive and dorsal nucleus of the lateral lemniscus. This study identifies for the first time those specific regions of brainstem nuclei providing input to the central nucleus of the inferior colliculus that process FM2 information in the mustached bat. The primary outputs of the FM2 region project to the medial and dorsal divisions of the medial geniculate body. In sharp contrast to other mammals, we found little evidence of connections to the ventral division of the medial geniculate. Other regions receiving significant inputs from the FM2 area include the deep superior colliculus ipsilaterally and the ipsilateral lateral pontine nuclei. Some fibers also terminated near the midline in the dorsal midbrain periaqueductal gray. Sparse intrinsic connections were also seen to the ipsilateral dorsoposterior division of the central nucleus and to the contralateral inferior colliculus at a location homologous to the injection site in the anterolateral division. The finding that FM2 projections to the medial geniculate heavily favor the medial and dorsal divisions is consistent with the location of "FM-FM" delay-dependent facilitation neurons found by Olsen (Processing of Biosonar Information by the Medial Geniculate Body of the Mustached Bat, Pteronotus parnellii. Dissertation, Washington Univ., St. Louis, ''86) in these divisions, and with thalamocortical projection patterns in this species. These findings demonstrate that for the FM portions of the biosonar signal, a transformation from a tonotopic form of processing to a more specialized, convergent pattern of organization occurs at the level of the inferior colliculus ouputs.