Liu Xiuping, Wang Carol, Pan Christopher, Yan Jun
Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary Faculty of Medicine, Calgary, Alberta, Canada.
Cereb Cortex. 2015 Feb;25(2):545-53. doi: 10.1093/cercor/bht259. Epub 2013 Sep 17.
The auditory cortex exhibits frequency-specific plasticity over a life cycle. Although thalamocortical long-term potentiation (LTP) and depression (LTD) are components of a widely held model underlying the receptive field (RF) plasticity of cortical neurons, the model lacks direct supporting evidence. We show here that conventional high-frequency tetanic stimulation (TS) of the auditory thalamus induced long-term changes in cortical field excitatory postsynaptic potentials, including both LTP and LTD, in mice. Thalamic TS induced LTP when the stimulated thalamic and recorded cortical neurons were tuned to the same frequency and induced LTD when they were tuned to different frequencies. The thalamocortical LTP was N-methyl-d-aspartate-dependent, but the LTD also involved cortical γ-amino-butyric acidergic inhibition. Notably, the frequency-specificity of cortical LTP/LTD was in accordance with the frequency-specific plasticity of spike-based RFs of cortical neurons. Our results suggest that cortical LTP and LTD induced by thalamic induction can be a consequence of identical stimuli, occur in an input-specific manner, and account for frequency-specific remodeling of RFs of auditory cortical neurons.
听觉皮层在整个生命周期中表现出频率特异性可塑性。虽然丘脑皮质长时程增强（LTP）和长时程抑制（LTD）是广泛认可的皮层神经元感受野（RF）可塑性模型的组成部分，但该模型缺乏直接的支持证据。我们在此表明，对听觉丘脑进行传统的高频强直刺激（TS）可诱导小鼠皮层场兴奋性突触后电位发生长期变化，包括LTP和LTD。当受刺激的丘脑神经元和记录的皮层神经元调谐到相同频率时，丘脑TS诱导LTP；当它们调谐到不同频率时，则诱导LTD。丘脑皮质LTP依赖于N-甲基-D-天冬氨酸，但LTD也涉及皮层γ-氨基丁酸能抑制。值得注意的是，皮层LTP/LTD的频率特异性与皮层神经元基于尖峰的RF的频率特异性可塑性一致。我们的结果表明，丘脑诱导引起的皮层LTP和LTD可能是相同刺激的结果，以输入特异性方式发生，并解释了听觉皮层神经元RF的频率特异性重塑。
