Department of Anatomy and Neurobiology, Virginia Commonwealth University Medical Center, Richmond, Virginia 23298, USA.
J Neurosci. 2011 May 4;31(18):6842-9. doi: 10.1523/JNEUROSCI.1173-11.2011.
Monocular deprivation (MD) is a classic paradigm for experience-dependent cortical plasticity. One form is known as homeostatic plasticity, in which neurons innervated by the deprived eye show a remarkable capacity to compensate for degraded visual signals in an attempt to stabilize network activity. Although the evidence supporting homeostatic plasticity in visual cortex is extensive, it remains unclear whether neurons in subcortical visual structures respond to MD in a similar manner. Here we examined whether cells in the dorsal lateral geniculate nucleus (dLGN), the thalamic relay between the retina and visual cortex, show similar forms of experience-dependent homeostatic plasticity following MD. Two-week-old mice were monocularly deprived for a period of 5-7 d and miniature EPSCs (mEPSCs) were obtained from cells located in dLGN regions receiving input from the deprived or nondeprived eye. We found that MD promotes increases in the frequency and amplitude of mEPSCs and were restricted to the monocular segment contralateral to the deprived eye. These changes were accompanied by an increase in the probability of glutamate release at corticothalamic terminals that arise from the deprived visual cortex. Our findings indicate that homeostatic synaptic regulation from MD extends beyond cortical circuitry and shed light on how the brain modulates and integrates activity in the face of altered sensory experience.
单眼剥夺（MD）是一种经典的经验依赖性皮质可塑性范例。其中一种形式称为同型可塑性，即被剥夺眼支配的神经元具有显著的补偿受损视觉信号的能力，试图稳定网络活动。尽管支持视觉皮层同型可塑性的证据广泛存在，但仍不清楚皮质下视觉结构中的神经元是否以类似的方式对 MD 做出反应。在这里，我们研究了在 MD 后，背外侧膝状体核（dLGN）中的细胞是否表现出类似的经验依赖性同型可塑性。将 2 周龄的小鼠进行单眼剥夺 5-7 天，并从接收来自剥夺眼或非剥夺眼输入的 dLGN 区域中的细胞获得微小兴奋性突触后电流（mEPSC）。我们发现 MD 促进了 mEPSC 的频率和幅度增加，并且仅限于与剥夺眼相对的单眼节段。这些变化伴随着来自剥夺视觉皮层的皮质丘脑终端谷氨酸释放概率的增加。我们的发现表明，MD 的同型突触调节不仅限于皮质回路，并揭示了大脑如何在面对改变的感觉体验时调节和整合活动。
