Sensory experience alters cortical connectivity and synaptic function site specifically.
Sensory experience alters cortical connectivity and synaptic function site specifically.
复制标题
感官体验特异性改变皮层连通性和突触功能位点。
DOI：
10.1523/jneurosci.5143-06.2007
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发表时间：
2007-03-28
影响因子：
5.3
通讯作者：
Finnerty, Gerald T.
中科院分区：
文献类型：
--
作者：
Cheetham, Claire E. J.;Hammond, Martin S. L.;Edwards, Clarissa E. J.;Finnerty, Gerald T.
新皮层回路可以随着经历而改变。然而，突触强度的变化和神经元布线的修改，在成熟动物的经验依赖性可塑性的贡献仍然不清楚。我们修剪了大鼠的胡须，并进行了电生理记录后，胡须皮层地图的发展。微型EPSP的测量结果表明，在初级躯体感觉皮层的剥夺皮层和保留皮层的交界处，对2/3层锥体神经元的突触输入发生了改变。从成对的突触连接的锥体神经元进行全细胞记录，以研究2/3层锥体神经元之间的局部兴奋性连接的可能变化。在记录过程中用荧光染料填充神经元，并使用共聚焦显微镜和图像去卷积在三维中重建以识别推定的突触。我们发现，感觉剥夺诱导显着减少在剥夺皮层的第2/3层锥体神经元之间的连接，而没有大规模的，补偿性增加剩余的本地兴奋性连接的强度。一个明显不同的情况发生在备用皮层。连接强度增强，但局部兴奋性连接和每个连接的突触数量不变。我们的数据表明，局部兴奋性回路的改变增强了扩展到剥夺皮层的备用表示。此外，我们的研究结果提供了一个解释如何备用和剥夺皮层的感觉剥夺的反应可以在发达动物中分离。
Neocortical circuitry can alter throughout life with experience. However, the contributions of changes in synaptic strength and modifications in neuronal wiring to experience-dependent plasticity in mature animals remain unclear. We trimmed whiskers of rats and made electrophysiological recordings after whisker cortical maps have developed. Measurements of miniature EPSPs suggested that synaptic inputs to layer 2/3 pyramidal neurons were altered at the junction of deprived and spared cortex in primary somatosensory cortex. Whole-cell recordings were made from pairs of synaptically connected pyramidal neurons to investigate possible changes in local excitatory connections between layer 2/3 pyramidal neurons. The neurons were filled with fluorescent dyes during recording and reconstructed in three dimensions using confocal microscopy and image deconvolution to identify putative synapses. We show that sensory deprivation induces a striking reduction in connectivity between layer 2/3 pyramidal neurons in deprived cortex without large-scale, compensatory increases in the strength of remaining local excitatory connections. A markedly different situation occurs in spared cortex. Connection strength is potentiated, but local excitatory connectivity and synapse number per connection are unchanged. Our data suggest that alterations in local excitatory circuitry enhance the expansion of spared representations into deprived cortex. Moreover, our findings offer one explanation for how the responses of spared and deprived cortex to sensory deprivation can be dissociated in developed animals.