Effects of focal inactivation of dorsal or ventral layers of the lateral geniculate nucleus on cats' ability to see and fixate small targets.
Effects of focal inactivation of dorsal or ventral layers of the lateral geniculate nucleus on cats' ability to see and fixate small targets.
复制标题
外侧膝状核背侧或腹侧层的局部失活对猫看到和固定小目标的能力的影响。
DOI：
10.1152/jn.1998.80.4.2206
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Malpeli,JG
中科院分区：
文献类型：
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作者：
Tate,AK;Malpeli,JG
作者：Andrew K.和约瑟夫G. Malpeli。外侧膝状体核背侧或腹侧层的局灶性失活对猫看到和固定小目标能力的影响。神经生理学杂志。80：2206-2209，1998。为了揭示外侧膝状体核（LGN）的不同分区对视觉行为的贡献，用γ-氨基丁酸显微注射使A层或C层的节段失活，同时猫对视网膜稳定的光点进行扫视，这些光点位于视觉空间的受影响区域或相对半野的镜像对称位置。失活层A将对受影响位置中呈现的目标的扫视的成功率从82.4%降低到26.8%，而对对照半视野的扫视没有影响。扫视受影响的网站有降低的准确性和较长的启动潜伏期，往往是hypometric。相反，使C层失活不影响性能。来自所有条件的数据沿着沿着相同的扫视速度/幅度函数（“主序列”）下降，表明LGN失活引起定位缺陷，但不干扰扫视动力学。大脑皮层是A层的唯一目标，因此由A层失活引起的行为衰退一定与皮层活动的变化有关。失活层A大大降低了17和18区皮质顶盖细胞的大子集的活动，而很少有皮质顶盖细胞依赖于C层的视觉驱动的活动。这些行为和电生理数据之间的相似之处沿着，以及上级丘在扫视眼球运动中的中心作用，表明皮质顶盖通路参与了A层阻滞导致的缺陷和剩余能力。
Tate, Andrew K. and Joseph G. Malpeli.Effects of focal inactivation of dorsal or ventral layers of the lateral geniculate nucleus on cats' ability to see and fixate small targets.J. Neurophysiol.80: 2206–2209, 1998. To reveal contributions of different subdivisions of the lateral geniculate nucleus (LGN) to visuomotor behavior, segments of either layer A or the C layers were inactivated with microinjections of γ-aminobutyric acid while cats made saccades to retinally stabilized spots of light placed either in affected regions of visual space or mirror-symmetric locations in the opposite hemifield. Inactivating layer A reduced the success rate for saccades to targets presented in affected locations from 82.4 to 26.8% while having no effect on saccades to the control hemifield. Saccades to affected sites had reduced accuracy and longer initiation latency and tended to be hypometric. In contrast, inactivating C layers did not affect performance. Data from all conditions fell along the same saccade velocity/amplitude function (“main sequence”), suggesting that LGN inactivations cause localization deficits, but do not interfere with saccade dynamics. Cerebral cortex is the only target of the A layers, so behavioral decrements caused by inactivating layer A must be related to changes in cortical activity. Inactivating layer A substantially reduces the activity of large subsets of corticotectal cells in areas 17 and 18, whereas few corticotectal cells depend on C layers for visually driven activity. The parallels between these behavioral and electrophysiological data along with the central role of the superior colliculus in saccadic eye movements suggests that the corticotectal pathway is involved in both deficits and remaining capacities resulting from blockade of layer A.