Optical imaging of retinotopic maps in a small songbird, the zebra finch.
Optical imaging of retinotopic maps in a small songbird, the zebra finch.
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DOI：
10.1371/journal.pone.0011912
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发表时间：
2010-08-04
期刊：
影响因子：
3.7
通讯作者：
Löwel S
中科院分区：
文献类型：
--
作者：
Keary N;Voss J;Lehmann K;Bischof HJ;Löwel S
哺乳动物的初级视觉皮层的特征是视野的视网膜异位表示。因此，人们推测，视觉皮层，即鸟类视觉皮层的同源物，也包含这样一个视网膜定位图。我们首次通过对斑马雀（一种眼睛侧向放置的小鸣禽）的内在信号进行光学成像来检验这一点。除了视觉影像外，我们还可视化了视神经顶盖的视网膜定位图，视神经顶盖与哺乳动物的上丘是同源的。对于视顶盖，我们的结果证实了先前基于解剖学研究和传统电生理学的地形描述。在视觉范围内，我们的实验所揭示的视网膜病变以前没有令人信服的说明。视野额部（0°±30°方位角）未在视网膜定位图中显示。在30°~ 60°方位的视野中，视场放大比在更侧向的区域更强。只有高度在地平线以上约20°至40°之间的刺激才会引起神经元的激活。其他高度的激活被首选区域的激活所掩盖。最有趣的是，我们在视觉皮层中观察到不止一种视觉空间的视网膜定位表示，这表明鸟类的视觉皮层，就像哺乳动物的视觉皮层一样，除了其分层结构外，可能还显示出一些平行于表面的区隔。我们的结果表明，光学成像方法也适用于小型鸣禽。我们获得了鸟类视网膜定位图的更详细的图片，特别是在视觉鞘的功能神经元组织。我们的研究结果通过显示两个区域之间存在功能对应性来支持视觉细胞和视觉皮层同源性的概念，但也提出了基于鸟类和哺乳动物视网膜异位表征之间相当大的差异的问题。
The primary visual cortex of mammals is characterised by a retinotopic representation of the visual field. It has therefore been speculated that the visual wulst, the avian homologue of the visual cortex, also contains such a retinotopic map. We examined this for the first time by optical imaging of intrinsic signals in zebra finches, a small songbird with laterally placed eyes. In addition to the visual wulst, we visualised the retinotopic map of the optic tectum which is homologue to the superior colliculus in mammals. For the optic tectum, our results confirmed previous accounts of topography based on anatomical studies and conventional electrophysiology. Within the visual wulst, the retinotopy revealed by our experiments has not been illustrated convincingly before. The frontal part of the visual field (0°±30° azimuth) was not represented in the retinotopic map. The visual field from 30°–60° azimuth showed stronger magnification compared with more lateral regions. Only stimuli within elevations between about 20° and 40° above the horizon elicited neuronal activation. Activation from other elevations was masked by activation of the preferred region. Most interestingly, we observed more than one retinotopic representation of visual space within the visual wulst, which indicates that the avian wulst, like the visual cortex in mammals, may show some compartmentation parallel to the surface in addition to its layered structure. Our results show the applicability of the optical imaging method also for small songbirds. We obtained a more detailed picture of retinotopic maps in birds, especially on the functional neuronal organisation of the visual wulst. Our findings support the notion of homology of visual wulst and visual cortex by showing that there is a functional correspondence between the two areas but also raise questions based on considerable differences between avian and mammalian retinotopic representations.
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影响因子：
2.9
作者：
JASSIKGE.D;GUICHARD, J
通讯作者：
GUICHARD, J
影响因子：
2.5
作者：
KARTEN, HJ;HODOS, W;REVZIN, AM
通讯作者：
REVZIN, AM
影响因子：
2.9
作者：
Liu, GB;Pettigrew, JD
通讯作者：
Pettigrew, JD
DOI：
10.1007/bf00604008
发表时间：
1988-01-01
影响因子：
2.1
作者：
BISCHOF, HJ
通讯作者：
BISCHOF, HJ
DOI：
10.1113/expphysiol.1976.sp002366
发表时间：
1976-01-01
影响因子：
--
作者：
CLARKE, PGH;WHITTERIDGE, D
通讯作者：
WHITTERIDGE, D