Multiple sites of adaptive plasticity in the owl's auditory localization pathway
Multiple sites of adaptive plasticity in the owl's auditory localization pathway
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DOI：
10.1523/jneurosci.0480-04.2004
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发表时间：
2004-08-04
影响因子：
5.3
通讯作者：
Knudsen, EI
中科院分区：
文献类型：
--
作者：
DeBello, WM;Knudsen, EI
在谷仓猫头鹰的中脑听觉定位通路中，听觉空间图从下丘外核(ICx)传递到视顶盖的深层和中间层(OT)，并从这些层传递到浅层。在OT内，听觉空间地图与视觉空间地图对齐。饲养有棱镜移位视野的幼年谷仓猫头鹰会导致OT中听觉调谐的渐进性变化，这往往会使听觉空间图与棱镜移位的视觉空间图重新对准。这种适应性可塑性的唯一已知部位是在ICx，在那里听觉系统首先创建一张空间地图。在这项研究中，我们确定了OT中的一个额外的可塑性部位。在幼年后期开始经历棱镜的猫头鹰中，OT浅层的听觉调谐的适应性变化超过了OT或ICx深层的适应性变化。这些猫头鹰的解剖结果表明，固有的OT连接的地形在适应方向上发生了系统性的改变。在幼年猫头鹰中，OT的可塑性随着ICx的可塑性的降低而增加。由于这两个部位的可塑性在成年人中都显示出显著的下降，这些结果表明，随着年龄的增长，听觉地图可塑性的下降首先发生在ICx，然后在更高的水平，即OT。
In the midbrain auditory localization pathway of the barn owl, a map of auditory space is relayed from the external nucleus of the inferior colliculus (ICX) to the deep and intermediate layers of the optic tectum (OT) and from these layers to the superficial layers. Within the OT, the auditory space map aligns with a visual map of space. Raising young barn owls with a prismatic displacement of the visual field leads to progressive changes in auditory tuning in the OT that tend to realign the auditory space map with the prismatically displaced visual space map. The only known site of this adaptive plasticity is in the ICX, in which the auditory system first creates a map of space. In this study, we identified an additional site of plasticity in the OT. In owls that experienced prisms beginning late in the juvenile period, adaptive shifts in auditory tuning in the superficial layers of the OT exceeded the adaptive shifts that occurred in the deep layers of the OT or in the ICX. Anatomical results from these owls demonstrated that the topography of intrinsic OT connections was systematically altered in the adaptive direction. In juvenile owls, plasticity in the OT increased as plasticity in the ICX decreased. Because plasticity at both sites has been shown to decline substantially in adults, these results suggest that an age-dependent decrease in auditory map plasticity occurs first in the ICX and later at the higher level, in the OT.