The Effects of GluA1 Deletion on the Hippocampal Population Code for Position
The Effects of GluA1 Deletion on the Hippocampal Population Code for Position
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DOI：
10.1523/jneurosci.6460-11.2012
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发表时间：
2012-06-27
影响因子：
5.3
通讯作者：
Mehta, Mayank R.
中科院分区：
文献类型：
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作者：
Resnik, Evgeny;McFarland, James M.;Mehta, Mayank R.
AMPA受体的GluA 1亚基（AMPARs）对海马突触传递和可塑性至关重要。在这里，我们测量了单个单位的活动，从海马CA 1区，而GluA 1基因敲除（GluA 1（-/-））和野生型（WT）小鼠穿越线性轨道。虽然总体放电率相似，但与WT神经元相比，GluA 1（-/-）神经元更可能在爆发中尖峰，但爆发频率较低。GluA 1（-/-）神经元表现出大幅度减少的空间和方向选择性的所有措施相比，野生型神经元。与单神经元特性的这些改变一致，GluA 1（-/-）中位置的群体代码的准确性大幅降低，但预测随着群体大小的增加，其接近WT的准确性。空间的绝对代表性，独立于运动方向，在GluA 1（-/-）小鼠中大大减少，预计即使在更大的群体中也会保持减少。最后，我们发现，速率图的GluA 1（-/-）神经元显示增加试验的变异性，但减少经验的可塑性与WT相比。这些结果揭示了含GluA 1的AMPAR对单个位置细胞和海马群体空间编码的关键贡献，这可以解释在这些小鼠中观察到的选择性行为障碍。
The GluA1 subunit of AMPA receptors (AMPARs) is critical for hippocampal synaptic transmission and plasticity. Here, we measured the activity of single units from the CA1 region of the hippocampus while GluA1 knock-out (GluA1(-/-)) and wild-type (WT) mice traversed a linear track. Although overall firing rates were similar, GluA1(-/-) neurons were more likely to spike in bursts, but at lower burst frequencies, compared with WT neurons. GluA1(-/-) neurons showed large reductions in all measures of spatial and directional selectivity compared with WT neurons. Consistent with these alterations of single-neuron properties, the accuracy of the population code for position was substantially reduced in GluA1(-/-), yet it is predicted to approach the accuracy of WT with increasing population size. The absolute representation of space, independent of movement direction, was greatly diminished in GluA1(-/-) mice and is predicted to remain reduced even for larger populations. Finally, we found that the rate maps of GluA1(-/-) neurons showed increased trial-by-trial variability but reduced experiential plasticity compared with the WT. These results reveal the critical contribution of GluA1-containing AMPARs to individual place cells and the hippocampal population code for space, which could explain the selective behavioral impairments observed in these mice.