Synaptic plasticity in a cerebellum-like structure depends on temporal order
Synaptic plasticity in a cerebellum-like structure depends on temporal order
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DOI：
10.1038/387278a0
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发表时间：
1997-05-15
期刊：
影响因子：
64.8
通讯作者：
Grant, K
中科院分区：
文献类型：
--
作者：
Bell, CC;Han, VZ;Grant, K
鱼类的小脑样结构似乎充当自适应感觉处理器，其中产生关于感觉输入的学习预测并从实际感觉输入中减去，从而使未预测的输入脱颖而出（1-3）。将感觉输入与中央起源的预测信号（例如与运动命令相关的必然放电信号）配对，导致对预测信号的神经响应单独是先前配对的感觉响应的“负面图像”。将这些“负面图像”添加到实际感觉输入，最小化对可预测感觉特征的神经响应。在细胞水平，感觉输入被传递到浦肯野样细胞的基底区，而预测信号通过平行纤维传递到相同细胞的顶端树突（4）。负像的产生可以用平行纤维突触的可塑性来解释（5-7）。我们在这里表明，这种可塑性存在于电感觉叶的mormyrid电鱼，它具有必要的属性，这样一个模型：它是可逆的，反hebbian（兴奋性突触后电位（EPSP）与突触后尖峰配对后被压抑）和紧密依赖于序列的前和突触后事件，抑郁症的发生只有当突触后尖峰以下EPSP发病60毫秒内。
Cerebellum-like structures in fish appear to act as adaptive sensory processors, in which learned predictions about sensory input are generated and subtracted from actual sensory input, allowing unpredicted inputs to stand out(1-3). Pairing sensory input with centrally originating predictive signals, such as corollary discharge signals linked to motor commands, results in neural responses to the predictive signals alone that are 'negative images' of the previously paired sensory responses, Adding these 'negative images' to actual sensory inputs minimizes the neural response to predictable sensory features, At the cellular level, sensory input is relayed to the basal region of Purkinje-like cells, whereas predictive signals are relayed by parallel fibres to the apical dendrites of the same cells(4). The generation of negative images could be explained by plasticity at parallel fibre synapses(5-7). We show here that such plasticity exists in the electrosensory lobe of mormyrid electric fish and that it has the necessary properties for such a model: it is reversible, anti-hebbian (excitatory postsynaptic potentials (EPSPs) are depressed after pairing with a postsynaptic spike) and tightly dependent on the sequence of pre- and postsynaptic events, with depression occurring only if the postsynaptic spike follows EPSP onset within 60 ms.