Motor Training Promotes Both Synaptic and Intrinsic Plasticity of Layer II/III Pyramidal Neurons in the Primary Motor Cortex.
Motor Training Promotes Both Synaptic and Intrinsic Plasticity of Layer II/III Pyramidal Neurons in the Primary Motor Cortex.
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DOI：
10.1093/cercor/bhw134
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发表时间：
2016-08
期刊：
影响因子：
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通讯作者：
Mitsushima D
中科院分区：
文献类型：
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作者：
Kida H;Tsuda Y;Ito N;Yamamoto Y;Owada Y;Kamiya Y;Mitsushima D
运动技能训练诱导初级运动皮层（M1）树突棘的结构可塑性。为了进一步分析突触和内在可塑性在层II/III区的M1，我们进行大鼠转子杆测试，然后制备急性脑切片。运动技能在训练后2天内持续改善。电压钳分析显示，与未训练大鼠相比，训练1 d大鼠的α-氨基-3-羟基-5-甲基-4-异恶唑丙酸/N-甲基-d-天冬氨酸（AMPA/NMDA）比值显著升高，EPSC波幅也显著减小，提示运动学习早期突触后AMPA受体增加。与未训练的对照组相比，训练2天的大鼠表现出显着较高的微型EPSC的振幅和频率。配对脉冲分析进一步表明，在2天的训练大鼠较低的利率，这表明增加突触前谷氨酸释放在学习的后期。一天训练的大鼠表现出降低的微型IPSC频率和增加的成对脉冲分析诱发的IPSC，提示突触前γ-氨基丁酸（GABA）释放的短暂减少。此外，电流钳分析显示，较低的静息膜电位，较高的尖峰阈值，和更深的后超极化1天的训练大鼠，而2天的训练大鼠表现出较高的膜电位，这表明在内在特性的动态变化。我们目前的研究结果表明，运动训练后，M1层II/III神经元的多巴胺能，GABA能和内在可塑性的动态变化。
Motor skill training induces structural plasticity at dendritic spines in the primary motor cortex (M1). To further analyze both synaptic and intrinsic plasticity in the layer II/III area of M1, we subjected rats to a rotor rod test and then prepared acute brain slices. Motor skill consistently improved within 2 days of training. Voltage clamp analysis showed significantly higher α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-methyl-d-aspartate (AMPA/NMDA) ratios and miniature EPSC amplitudes in 1-day trained rats compared with untrained rats, suggesting increased postsynaptic AMPA receptors in the early phase of motor learning. Compared with untrained controls, 2-days trained rats showed significantly higher miniature EPSC amplitude and frequency. Paired-pulse analysis further demonstrated lower rates in 2-days trained rats, suggesting increased presynaptic glutamate release during the late phase of learning. One-day trained rats showed decreased miniature IPSC frequency and increased paired-pulse analysis of evoked IPSC, suggesting a transient decrease in presynaptic γ-aminobutyric acid (GABA) release. Moreover, current clamp analysis revealed lower resting membrane potential, higher spike threshold, and deeper afterhyperpolarization in 1-day trained rats—while 2-days trained rats showed higher membrane potential, suggesting dynamic changes in intrinsic properties. Our present results indicate dynamic changes in glutamatergic, GABAergic, and intrinsic plasticity in M1 layer II/III neurons after the motor training.