Laboratory of Neuroplasticity and Neuroproteomics, KU Leuven, 3000, Leuven, Belgium.
J Comp Neurol. 2014 Mar;522(4):950-70. doi: 10.1002/cne.23455.
Monocular enucleation (ME) drastically affects the contralateral visual cortex, where plasticity phenomena drive specific adaptations to compensate for the unilateral loss of vision. In adult mice, complete reactivation of deprived visual cortex involves an early visually driven recovery followed by multimodal plasticity 3 to 7 weeks post ME (Van Brussel et al. [2011] Cereb. Cortex 21:2133-2146). Here, we specifically investigated the age dependence of the onset and the exact timing of both ME-induced reactivation processes by comparing cortical activity patterns of mice enucleated at postnatal day (P) 45, 90, or 120. A swifter open-eye potentiated reactivation characterized the binocular visual cortex of P45 mice. Nevertheless, even after 7 weeks, the reactivation remained incomplete, especially in the monocular cortex medial to V1. In comparison with P45, emergent cross-modal participation was demonstrated in P90 animals, although robust reactivation similar to enucleated adults (P120) was not achieved yet. Concomitantly, at 7 weeks post ME, somatosensory and auditory cortex shifted from a hypoactive state in P45 to hyperactivity in P120. Thus, we provide evidence for a presensitive period in which gradual recruitment of cross-modal recovery upon long-term ME coincides with the transition from adolescence to adulthood in mice.
单眼切除术（ME）会严重影响对侧视皮层，在对侧视皮层中，可塑性现象会驱动特定的适应，以补偿单侧视力丧失。在成年小鼠中，剥夺视觉皮层的完全再激活涉及早期视觉驱动的恢复，随后是多模态可塑性，在 ME 后 3 至 7 周（Van Brussel 等人，[2011]Cereb.Cortex21:2133-2146）。在这里，我们通过比较在出生后第 45、90 或 120 天进行单眼切除术的小鼠的皮层活动模式，特别研究了这两个 ME 诱导的再激活过程的起始和确切时间的年龄依赖性。在 P45 小鼠的双眼视觉皮层中，更快的睁眼增强再激活特征明显。然而，即使在 7 周后，再激活仍然不完全，特别是在 V1 内侧的单眼皮层。与 P45 相比，P90 动物表现出新兴的跨模态参与，但尚未达到与成年单眼切除术（P120）相似的强烈再激活。同时，在 ME 后 7 周，体感和听觉皮层从 P45 的低活动状态转变为 P120 的高活动状态。因此，我们提供了证据表明，在一个敏感时期，长期 ME 后跨模态恢复的逐渐招募与小鼠从青春期到成年期的过渡相吻合。
