Roy S A, Alloway K D
Department of Neuroscience and Anatomy, Penn State University College of Medicine, Hershey, Pennsylvania 17033-2255, USA.
J Neurosci. 2001 Apr 1;21(7):2462-73. doi: 10.1523/JNEUROSCI.21-07-02462.2001.
To assess the impact of thalamic synchronization on cortical responsiveness, we used conditional cross-correlation analysis to measure the probability of neuronal discharges in somatosensory cortex as a function of the time between discharges in pairs of simultaneously recorded neurons in the ventrobasal thalamus. Among 26 neuronal trios, we found that thalamocortical efficacy after synchronous thalamic activity was nearly twice as large as the efficacy rate obtained when pairs of thalamic neurons discharged asynchronously. Nearly half of these neuronal trios displayed cooperative effects in which the cortical discharge probability after synchronous thalamic events was larger than could be predicted from the efficacy rate of individual thalamic discharges. In these cases of heterosynaptic cooperativity, thalamocortical efficacy declined to asymptotic levels when the interspike intervals were >6-8 msec. These results indicate that thalamic synchronization has a significant impact on cortical responsiveness and suggest that neuronal synchronization may play a critical role in the transmission of sensory information from one brain region to another.
为了评估丘脑同步性对皮质反应性的影响，我们使用条件互相关分析来测量体感皮质中神经元放电的概率，该概率是腹侧基底丘脑同时记录的神经元对之间放电时间的函数。在26个神经元三联体中，我们发现丘脑同步活动后的丘脑皮质效能几乎是丘脑神经元对异步放电时获得的效能率的两倍。这些神经元三联体中近一半表现出协同效应，即丘脑同步事件后的皮质放电概率大于根据单个丘脑放电的效能率所预测的值。在这些异突触协同作用的情况下，当峰间期>6 - 8毫秒时，丘脑皮质效能下降至渐近水平。这些结果表明丘脑同步性对皮质反应性有显著影响，并提示神经元同步性可能在感觉信息从一个脑区传递到另一个脑区的过程中起关键作用。
