Prolonged synaptic integration in perirhinal cortical neurons
Prolonged synaptic integration in perirhinal cortical neurons
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DOI：
10.1152/jn.2000.83.6.3294
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发表时间：
2000-06-01
影响因子：
2.5
通讯作者：
Brown, TH
中科院分区：
文献类型：
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作者：
Beggs, JM;Moyer, JR;Brown, TH
大鼠嗅周皮层（PR）的第II/III层含有大量的迟发性（LS）锥体神经元。当注入去极化电流阶跃时，这些LS单元通常从电流阶跃开始延迟尖峰一秒或多秒，然后在阶跃的持续时间内维持激发。这种延迟和持续放电的模式表明LS细胞在时间学习中具有特定的计算作用。该假设预测并要求一些II/III层神经元也应该表现出延迟和持续的尖峰信号，以响应一系列兴奋性突触输入。在这里，我们使用视觉引导的大鼠PR脑切片的全细胞记录来测试这一预测。大多数LS细胞（26个中的19个）表现出对突触刺激的延迟尖峰（从串开始的> Is潜伏期），并且这些细胞中的大多数（19个中的13个）还显示持续突触串的持续时间（5 - 10 s持续时间）的持续放电。在脊椎动物神经元中，对长突触串的延迟和持续放电反应以前没有报道过。这些数据与我们的模型一致，即包含晚期尖峰神经元的电路可以用于在联想学习期间编码长时间间隔。
Layer II/III of rat perirhinal cortex (PR) contains numerous late-spiking (LS) pyramidal neurons. When injected with a depolarizing current step, these LS cells typically delay spiking for one or more seconds from the onset of the current step and then sustain firing for the duration of the step. This pattern of delayed and sustained firing suggested a specific computational role for LS cells in temporal learning. This hypothesis predicts and requires that some layer II/III neurons should also exhibit delayed and sustained spiking in response to a train of excitatory synaptic inputs. Here we tested this prediction using visually guided, whole cell recordings from rat PR brain slices. Most LS cells (19 of 26) exhibited delayed spiking to synaptic stimulation (>1 s latency from the train onset), and the majority of these cells (13 of 19) also showed sustained firing that persisted for the duration of the synaptic train (5-10 s duration). Delayed and sustained firing in response to long synaptic trains has not been previously reported in vertebrate neurons. The data are consistent with our model that a circuit containing late spiking neurons can be used for encoding long time intervals during associative learning.