Shift in the Balance between Excitation and Inhibition during Sensory Adaptation of S1 Neurons
Shift in the Balance between Excitation and Inhibition during Sensory Adaptation of S1 Neurons
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DOI：
10.1523/jneurosci.2646-08.2008
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发表时间：
2008-12-03
影响因子：
5.3
通讯作者：
Lampl, Ilan
中科院分区：
文献类型：
--
作者：
Heiss, Jaime E.;Katz, Yonatan;Lampl, Ilan
感觉器官的持续刺激导致神经反应沿感觉通路的适应。皮质适应是否同样影响兴奋和抑制，目前还知之甚少。我们通过对麻醉大鼠桶状皮质神经元的贴片记录，在重复刺激主要胡须的同时，研究了这个问题。我们发现，抑制比兴奋更能适应，导致两者之间的平衡向兴奋转移。丘脑放电潜伏期与皮层诱发兴奋和抑制潜伏期的比较有力地表明，抑制的适应性主要来自抑制性突触的抑制，而不是抑制性细胞的放电的适应性。诱发电导的差异性适应使平衡向激发方向移动，这可能是一种增益机制，在持续刺激期间增强阈值下的反应，尽管兴奋程度大大降低。
Sustained stimulation of sensory organs results in adaptation of the neuronal response along the sensory pathway. Whether or not cortical adaptation affects equally excitation and inhibition is poorly understood. We examined this question using patch recordings of neurons in the barrel cortex of anesthetized rats while repetitively stimulating the principal whisker. We found that inhibition adapts more than excitation, causing the balance between them to shift toward excitation. A comparison of the latency of thalamic firing and evoked excitation and inhibition in the cortex strongly suggests that adaptation of inhibition results mostly from depression of inhibitory synapses rather than adaptation in the firing of inhibitory cells. The differential adaptation of the evoked conductances that shifts the balance toward excitation may act as a gain mechanism which enhances the subthreshold response during sustained stimulation, despite a large reduction in excitation.