Long-term potentiation induces expanded movement representations and dendritic hypertrophy in layer V of rat sensorimotor neocortex
Long-term potentiation induces expanded movement representations and dendritic hypertrophy in layer V of rat sensorimotor neocortex
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DOI：
10.1093/cercor/bhh020
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发表时间：
2004-05-01
期刊：
影响因子：
3.7
通讯作者：
Teskey, GC
中科院分区：
文献类型：
--
作者：
Monfils, MH;VandenBerg, PM;Teskey, GC
虽然长期增强（LTP）是目前研究最广泛的学习突触机制模型，但关于LTP对皮层组织的直接影响的报道很少。本研究表明，多突触增强与皮层内微刺激诱导的大鼠前肢运动和V层锥体细胞树突物质增加的新皮层区域扩大有关。大鼠在胼胝体（中线）携带一个刺激电极，在右侧前肢尾侧区（CFA）携带一个记录电极。每只大鼠接受15天的高频刺激（HFS）或处理。在刺激或处理前后15天分别记录右半球经胼胝体通路的诱发电位。在最后一次刺激后，使用高分辨率皮质内微刺激（ICMS）确定左CFA的运动表征，然后对大脑进行高尔基-考克斯染色。我们的研究结果表明，突触修饰导致更多的新皮层区域参与运动表征，并增加了第三层和第五层树突形态的几种测量。这项研究揭示了人工学习模型、感受野特征和感觉运动皮层树突形态之间的相互作用。
While long-term potentiation (LTP) is currently the most widely investigated model of the synaptic mechanisms underlying learning, there is a paucity of reports on the direct effects of LTP on cortical organization. Here we show that strengthening polysynaptic potentiation correlates with an expanded neocortical area that responds to intracortical microstimulation-induced movements of rat forelimb and increased dendritic material in layer V pyramidal cells. Rats carried a stimulating electrode in the corpus callosum (midline), and a recording electrode in the right caudal forelimb area (CFA). Each rat received 15 days of either high frequency stimulation (HFS) or handling. Evoked potentials of the transcallosal pathway were recorded in the right hemisphere before and after 15 days of stimulation or handling. Following the last stimulation, movement representations were determined in the left CFA using high-resolution intracortical microstimulation (ICMS) and then the brains were processed for Golgi-Cox staining. Our results show that synaptic modification results in a recruitment of more neocortical area into movement representations and increases in several measures of dendritic morphology in layers III and V. This study sheds light on the interaction between artificial models of learning, receptive field characteristics and dendritic morphology in the sensorimotor cortex.