Facilitating sensory responses in developing mouse somatosensory barrel cortex
Facilitating sensory responses in developing mouse somatosensory barrel cortex
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DOI：
10.1152/jn.00013.2007
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发表时间：
2007-04-01
影响因子：
2.5
通讯作者：
Petersen, Carl C. H.
中科院分区：
文献类型：
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作者：
Borgdorff, Aren J.;Poulet, James F. A.;Petersen, Carl C. H.
与P13-P21小鼠相比，单须偏转诱发的桶状皮质感觉反应幅度更小，分布面积更小。然而，在P7-P12小鼠中，重复的10hz刺激或成对的脉冲须刺激引起了促进的感觉反应，而在P13-P21小鼠中观察到的感觉反应则是抑制的。这种促进作用发生在第一次刺激后300-1,000 ms的间隔时间内，并通过全细胞记录、电压敏感染料成像和钙敏感染料成像进行测量。促进反应不仅幅度更大，而且在更大的皮质区域内传播。局部应用降低皮质兴奋性的药物可阻断这种促进作用。局部皮层微刺激可以代替第一次触须刺激，产生促进的感觉反应。P7-P12小鼠重复性感觉刺激引起的感觉反应增强可能与发育中的皮层回路的活动依赖性规范有关。此外，促进的感觉反应允许较长的整合时间来处理感觉加工，这与小鼠在出生后早期发育过程中的缓慢行为相适应。
The sensory responses in the barrel cortex of mice aged postnatal day (P)7-P12 evoked by a single whisker deflection are smaller in amplitude and spread over a smaller area than those measured in P13-P21 mice. However, repetitive 10-Hz stimulation or paired pulse whisker stimulation in P7-P12 mice evoked facilitating sensory responses, contrasting with the depressing sensory responses observed in P13-P21 mice. This facilitation occurred during an interval ranging 300-1,000 ms after the first stimulus and was measured using whole cell recordings, voltage-sensitive dye imaging, and calcium-sensitive dye imaging. The facilitated responses were not only larger in amplitude but also propagated over a larger cortical area. The facilitation could be blocked by local application of pharmacological agents reducing cortical excitability. Local cortical microstimulation could substitute for the first whisker stimulus to produce a facilitated sensory response. The enhanced sensory responses evoked by repetitive sensory stimuli in P7-P12 mice may contribute to the activity-dependent specification of the developing cortical circuits. In addition, the facilitating sensory responses allow long integration times for sensory processing compatible with the slow behavior of mice during early postnatal development.