Circuits that innervate excitatory-inhibitory cells in the inferior colliculus obtained with in vivo whole cell recordings.
Circuits that innervate excitatory-inhibitory cells in the inferior colliculus obtained with in vivo whole cell recordings.
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DOI：
10.1523/jneurosci.5735-12.2013
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发表时间：
2013-04-10
期刊：
影响因子：
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通讯作者：
Pollak GD
中科院分区：
文献类型：
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作者：
Li N;Pollak GD
被一只耳朵刺激而被另一只耳朵抑制的神经元，称为EI神经元，对耳间强度差异（IID）敏感，动物使用这种线索来定位高频。EI神经元首先在外侧上级橄榄（LSO）中形成，然后将兴奋性投射发送到外侧丘系背核（DNLL）和下丘（IC），这两个都含有大量EI细胞。我们评估的输入，支配EI细胞在IC的墨西哥无尾蝙蝠，Tadarida brasilensis墨西哥，在体内的全细胞记录，我们从中获得兴奋性和抑制性电导。我们发现，在大多数IC细胞的基本EI属性是从LSO继承，但每种类型的EI细胞也受同侧或对侧DNLL，以及额外的兴奋性和抑制性输入单耳核。我们确定了三种EI类型，其中每种类型接收一组与其他类型不同的投影。为了评估各种投影在生成双耳响应中所起的作用，我们使用建模来计算来自电导的预测响应。然后，我们从计算中省略了一个电导，以评估该输入对双耳响应的贡献程度。我们发现，在各种类型的EI属性的形成是复杂的，并且一些预测施加这样的微妙的影响，他们不能被检测到与细胞外记录，甚至从细胞内记录的突触后电位。
Neurons excited by stimulation of one ear and suppressed by the other, called EI neurons, are sensitive to interaural intensity disparities (IIDs), the cues animals use to localize high frequencies. EI neurons are first formed in lateral superior olive (LSO), which then sends excitatory projections to the dorsal nucleus of the lateral lemniscus (DNLL) and the inferior colliculus (IC), both of which contain large populations of EI cells. We evaluate the inputs that innervate EI cells in the IC of Mexican free-tailed bats, Tadarida brasilensis mexicana, with in vivo whole cell recordings from which we derived excitatory and inhibitory conductances. We show that the basic EI property in the majority of IC cells is inherited from LSO, but each type of EI cell is also innervated by the ipsi- or contralateral DNLL, as well as additional excitatory and inhibitory inputs from monaural nuclei. We identify three EI types, where each type receives a set of projections that are different from the other types. To evaluate the role that the various projections played in generating binaural responses, we used modeling to compute a predicted response from the conductances. We then omitted one of the conductances from the computation to evaluate the degree to which that input contributed to the binaural response. We show that formation of the EI property in the various types is complex, and that some projections exert such subtle influences that they could not have been detected with extracellular recordings or even from intracellular recordings of post-synaptic potentials.