Department of Physiology, Bengbu Medical College, Bengbu, Anhui Province 233000, China.
Mol Brain. 2013 Jan 3;6:2. doi: 10.1186/1756-6606-6-2.
Loss of a sensory input causes the hypersensitivity in other modalities. In addition to cross-modal plasticity, the sensory cortices without receiving inputs undergo the plastic changes. It is not clear how the different types of neurons and synapses in the sensory cortex coordinately change after input deficits in order to prevent loss of their functions and to be used for other modalities. We studied this subject in the barrel cortices from whiskers-trimmed mice vs. controls. After whisker trimming for a week, the intrinsic properties of pyramidal neurons and the transmission of excitatory synapses were upregulated in the barrel cortex, but inhibitory neurons and GABAergic synapses were downregulated. The morphological analyses indicated that the number of processes and spines in pyramidal neurons increased, whereas the processes of GABAergic neurons decreased in the barrel cortex. The upregulation of excitatory neurons and the downregulation of inhibitory neurons boost the activity of network neurons in the barrel cortex to be high levels, which prevent the loss of their functions and enhances their sensitivity to sensory inputs. These changes may prepare for attracting the innervations from sensory cortices and/or peripheral nerves for other modalities during cross-modal plasticity.
失去一种感觉输入会导致其他感觉方式的超敏反应。除了跨感觉模式可塑性外，没有接收输入的感觉皮质也会发生可塑性变化。目前尚不清楚在感觉皮质的输入缺陷后，不同类型的神经元和突触如何协调变化，以防止其功能丧失并用于其他感觉模式。我们在去毛的胡须 - 修剪的老鼠和对照组的桶状皮质中研究了这个问题。在修剪胡须一周后，桶状皮质中的锥体神经元的内在特性和兴奋性突触的传递被上调，但抑制性神经元和 GABA 能突触被下调。形态学分析表明，锥体神经元的过程和棘突数量增加，而 GABA 能神经元的过程减少。兴奋性神经元的上调和抑制性神经元的下调提高了桶状皮质中网络神经元的活性到高水平，这防止了它们功能的丧失，并增强了它们对感觉输入的敏感性。这些变化可能为在跨感觉模式可塑性期间吸引来自感觉皮质和/或周围神经的神经支配做好准备。
