Auditory and visual space maps in the cholinergic nucleus isthmi pars parvocellularis of the barn owl
Auditory and visual space maps in the cholinergic nucleus isthmi pars parvocellularis of the barn owl
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DOI：
10.1523/jneurosci.3946-06.2006
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发表时间：
2006-12-06
影响因子：
5.3
通讯作者：
Knudsen, Eric I.
中科院分区：
文献类型：
--
作者：
Maczko, Kristin A.;Knudsen, Phyllis F.;Knudsen, Eric I.
小细胞峡部核 (Ipc) 是一个中脑胆碱能核，与视顶盖 (OT) 具有相互的拓扑连接。 Ipc 神经元投射到 OT 中空间受限的列，基本上接触给定列中的所有 OT 层。先前的研究将 Ipc 描述为视觉处理器。我们发现，仓鸮的 IPC 对听觉和视觉刺激都有反应。听觉反应针对频率进行了广泛调整，但针对空间线索进行了大幅调整。我们测量了 Ipc 单元对双耳声音定位线索的调整，包括耳间时序差异 (ITD) 和耳间电平差异 (ILD)。 Ipc 中的单元根据 ITD 和 ILD 的特定值进行调整，并根据其 ITD 和 ILD 调整进行系统组织，形成空间图。听觉空间图与 IPC 中的视觉空间图对齐。这些结果表明 Ipc 对物体的空间位置进行编码，与刺激方式无关。这些发现与 Ipc 到 OT 的精确投射模式相结合，表明 Ipc 的作用是以空间特异性方式调节 OT 神经元的敏感性。
The nucleus isthmi pars parvocellularis (Ipc) is a midbrain cholinergic nucleus that shares reciprocal, topographic connections with the optic tectum (OT). Ipc neurons project to spatially restricted columns in the OT, contacting essentially all OT layers in a given column. Previous research characterizes the Ipc as a visual processor. We found that, in the barn owl, the Ipc responds to auditory as well as to visual stimuli. Auditory responses were tuned broadly for frequency, but sharply for spatial cues. We measured the tuning of Ipc units to binaural sound localization cues, including interaural timing differences (ITDs) and interaural level differences (ILDs). Units in the Ipc were tuned to specific values of both ITD and ILD and were organized systematically according to their ITD and ILD tuning, forming a map of space. The auditory space map aligned with the visual space map in the Ipc. These results demonstrate that the Ipc encodes the spatial location of objects, independent of stimulus modality. These findings, combined with the precise pattern of projections from the Ipc to the OT, suggest that the role of the Ipc is to regulate the sensitivity of OT neurons in a space-specific manner.