Long Michael A, Cruikshank Scott J, Jutras Michael J, Connors Barry W
Division of Biology and Medicine, Department of Neuroscience, Brown University, Providence, Rhode Island 02912, USA.
J Neurosci. 2005 Aug 10;25(32):7309-16. doi: 10.1523/JNEUROSCI.0375-05.2005.
Synchronous activity is common in the neocortex, although its significance, mechanisms, and development are poorly understood. Previous work showed that networks of electrically coupled inhibitory interneurons called low-threshold spiking (LTS) cells can fire synchronously when stimulated by metabotropic glutamate receptors. Here we found that the coordinated inhibition emerging from an activated LTS network could induce correlated spiking patterns among neighboring excitatory cells. Synchronous activity among LTS cells was absent at postnatal day 12 (P12) but appeared abruptly over the next few days. The rapid development of the LTS-synchronizing system coincided with the maturation of the inhibitory outputs and intrinsic membrane properties of the neurons. In contrast, the incidence and magnitude of electrical synapses remained constant between P8 and P15. The developmental transformation of LTS interneurons into a synchronous, oscillatory network overlaps with the onset of active somatosensory exploration, suggesting a potential role for this synchronizing system in sensory processing.
同步活动在新皮层中很常见，尽管其意义、机制和发育过程仍知之甚少。先前的研究表明，由电耦合抑制性中间神经元组成的网络，即低阈值发放（LTS）细胞，在受到代谢型谷氨酸受体刺激时能够同步放电。我们发现，激活的LTS网络产生的协同抑制可诱导相邻兴奋性细胞之间出现相关的放电模式。LTS细胞之间的同步活动在出生后第12天（P12）并不存在，但在接下来的几天中突然出现。LTS同步系统的快速发育与神经元抑制性输出和内在膜特性的成熟相一致。相比之下，电突触的发生率和大小在P8和P15之间保持恒定。LTS中间神经元向同步振荡网络的发育转变与主动体感探索的开始重叠，这表明该同步系统在感觉处理中可能发挥作用。
