本日は、運動学習中のAMPA受容体可塑性について勉強しました。本学人間総合科学学術院 人間総合科学研究群 ニューロサイエンス学位プログラムに入学したばかりの学生が論文紹介を担当しました。
Volume 105, Issue 5, 4 March 2020, Pages 895-908.e5
Cortical Synaptic AMPA Receptor Plasticity during Motor Learning
● In vivo imaging of AMPA receptors reveals high dynamics at individual synapses
● Motor learning induces potentiation of a clustered subset of dendritic spines
● Motor learning increases AMPA receptor levels in motor and visual cortex
● Plasticity of visual cortex during learning depends on visual input
Modulation of synaptic strength through trafficking of AMPA receptors (AMPARs) is a fundamental mechanism underlying synaptic plasticity, learning, and memory. However, the dynamics of AMPAR trafficking in vivo and its correlation with learning have not been resolved. Here, we used in vivo two-photon microscopy to visualize surface AMPARs in mouse cortex during the acquisition of a forelimb reaching task. Daily training leads to an increase in AMPAR levels at a subset of spatially clustered dendritic spines in the motor cortex. Surprisingly, we also observed increases in spine AMPAR levels in the visual cortex. There, synaptic potentiation depends on the availability of visual input during motor training, and optogenetic inhibition of visual cortex activity impairs task performance. These results indicate that motor learning induces widespread cortical synaptic potentiation by increasing the net trafficking of AMPARs into spines, including in non-motor brain regions.