Spatiotemporal receptive field organization in the lateral geniculate nucleus of cats and kittens
Spatiotemporal receptive field organization in the lateral geniculate nucleus of cats and kittens
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DOI：
10.1152/jn.1997.78.2.1045
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发表时间：
1997-08-01
影响因子：
2.5
通讯作者：
Freeman, RD
中科院分区：
文献类型：
--
作者：
Cai, DQ;DeAngelis, GC;Freeman, RD
我们研究了出生后4周和8周成年猫和幼猫膝状背外侧核（dLGN）记录的144个神经元的时空感受场组织。通过使用反向相关技术，我们计算了神经元的动作电位序列与在整个接受野中闪现的随机长亮条和暗条刺激序列之间的相互关系，从而获得了接受野的轮廓。LGN神经元的时空接受场分布通常表现为双相时间响应，以及经典的中心-环绕空间组织。对于非滞后细胞，反应的第一个时间阶段占主导地位，而对于滞后神经元，反应的第二个时间阶段通常是最大的。滞后和非滞后细胞之间的时间相位差解释了它们对闪现刺激反应的不同行为。大多数LGN细胞表现出一定程度的时空不可分离性，这意味着不能简单地将感受野视为空间波形和时间波形的产物。在这些情况下，环绕的响应通常相对于中心的响应延迟，并且在响应的时间过程中存在中心和环绕的一些混合。我们证明了传统的高斯差分（DOG）模型的简单扩展，其中环绕响应相对于中心响应延迟，很好地解释了这些发现。在发育方面，我们的分析表明，感受野结构的空间和时间方面的成熟具有明显不同的时间进程。出生后4周，大鼠LGN感受野的空间组织变化不大，但随着年龄的增长，周围的空间组织有微弱但明显的变小和增强的趋势。相反，产后4周后，颞区接受野结构发生了实质性的变化。从出生后4到8周，时间反应轮廓的形状发生变化，变得更加双相，但反应的潜伏期和持续时间保持不变。从出生后8周到成年，时间剖面的形状大致保持不变，但反应的潜伏期和持续时间都急剧下降。将我们的结果与皮层（17区）简单细胞的最新数据进行比较，我们发现LGN细胞的时间发育在简单细胞的时间成熟中占有相当大的一部分。
We have studied the spatiotemporal receptive-field organization of 144 neurons recorded from the dorsal lateral geniculate nucleus (dLGN) of adult cats and kittens at 4 and 8 wk postnatal. Receptive-field profiles were obtained with the use of a reverse correlation technique, in which we compute the cross-correlation between the action potential train of a neuron and a randomized sequence of long bright and dark bar stimuli that are flashed throughout the receptive field. Spatiotemporal receptive-field profiles of LGN neurons generally exhibit a biphasic temporal response, as well as the classical center-surround spatial organization. For nonlagged cells, the first temporal phase of the response dominates, whereas for lagged neurons, the second temporal phase of the response is typically the largest. This temporal phase difference between lagged and nonlagged cells accounts for their divergent behavior in response to flashed stimuli. Most LGN cells exhibit some degree of space-time inseparability, which means that the receptive field cannot simply be viewed as the product of a spatial waveform and a temporal waveform. In these cases, the response of the surround is typically delayed relative to that of the center, and there is some blending of center and surround during the time course of the response. We demonstrate that a simple extension of the traditional difference-of-Gaussians (DOG) model, in which the surround response is delayed relative to that of the center, accounts nicely for these findings. With regard to development, our analysis shows that spatial and temporal aspects of receptive field structure mature with markedly different time courses. After 4 wk postnatal, there is little change in the spatial organization of LGN receptive fields, with the exception of a weak, but significant, trend for the surround to become smaller and stronger with age. In contrast, there are substantial changes in temporal receptive-field structure after 4 wk postnatal. From 4 to 8 wk postnatal, the shape of the temporal response profile changes, becoming more biphasic, but the latency and duration of the response remain unchanged. From 8 wk postnatal to adulthood, the shape of the temporal profile remains approximately constant, but there is a dramatic decline in both the latency and duration of the response. Comparison of our results with recent data from cortical (area 17) simple cells reveals that the temporal development of LGN cells accounts for a substantial portion of the temporal maturation of simple cells.