Cortex is driven by weak but synchronously active thalamocortical synapses
Cortex is driven by weak but synchronously active thalamocortical synapses
复制标题
DOI：
10.1126/science.1124593
复制
发表时间：
2006-06-16
期刊：
影响因子：
56.9
通讯作者：
Sakmann, Bert
中科院分区：
文献类型：
--
作者：
Bruno, Randy M.;Sakmann, Bert
感觉刺激通过丘脑皮质投射到达大脑，这是一组被认为是新皮质中最强大的轴突。令人惊讶的是，这些轴突仅占皮质神经元上突触的15%。因此，丘脑皮质通路可能通过高效的丘脑皮质突触或通过皮层4层内的放大来实现其有效性。在大鼠躯体感觉皮层，我们在体内测量了由单个突触连接诱发的兴奋性突触后电位，发现丘脑皮层突触具有低效能。然而，会聚输入既多又同步，并且不需要皮层内放大。我们的研究结果表明，皮层激活的机制，丘脑输入可以单独驱动皮层。
Sensory stimuli reach the brain via the thalamocortical projection, a group of axons thought to be among the most powerful in the neocortex. Surprisingly, these axons account for only similar to 15% of synapses onto cortical neurons. The thalamocortical pathway might thus achieve its effectiveness via high-efficacy thalamocortical synapses or via amplification within cortical layer 4. In rat somatosensory cortex, we measured in vivo the excitatory postsynaptic potential evoked by a single synaptic connection and found that thalamocortical synapses have low efficacy. Convergent inputs, however, are both numerous and synchronous, and intracortical amplification is not required. Our results suggest a mechanism of cortical activation by which thalamic input alone can drive cortex.