Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA.
Applied Mathematics and Computational Science Graduate Program, School of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA.
Sci Rep. 2017 Mar 7;7:44006. doi: 10.1038/srep44006.
We examine the role of structural autapses, when a neuron synapses onto itself, in driving network-wide bursting behavior. Using a simple spiking model of neuronal activity, we study how autaptic connections affect activity patterns, and evaluate if controllability significantly affects changes in bursting from autaptic connections. Adding more autaptic connections to excitatory neurons increased the number of spiking events and the number of network-wide bursts. We observed excitatory synapses contributed more to bursting behavior than inhibitory synapses. We evaluated if neurons with high average controllability, predicted to push the network into easily achievable states, affected bursting behavior differently than neurons with high modal controllability, thought to influence the network into difficult to reach states. Results show autaptic connections to excitatory neurons with high average controllability led to higher burst frequencies than adding the same number of self-looping connections to neurons with high modal controllability. The number of autapses required to induce bursting was lowered by adding autapses to high degree excitatory neurons. These results suggest a role of autaptic connections in controlling network-wide bursts in diverse cortical and subcortical regions of mammalian brain. Moreover, they open up new avenues for the study of dynamic neurophysiological correlates of structural controllability.
我们研究了结构上的自突触（一个神经元与自身形成突触连接）在驱动网络范围爆发行为中的作用。使用神经元活动的简单尖峰模型，我们研究了自突触连接如何影响活动模式，并评估可控性是否显著影响自突触连接引起的爆发变化。向兴奋性神经元添加更多的自突触连接会增加尖峰事件的数量和网络范围的爆发数量。我们观察到兴奋性突触对爆发行为的贡献大于抑制性突触。我们评估了具有高平均可控性的神经元（预计将网络推向易于实现的状态）是否与具有高模态可控性的神经元（被认为影响难以达到的状态）对爆发行为的影响不同。结果表明，与向具有高模态可控性的神经元添加相同数量的自循环连接相比，向具有高平均可控性的兴奋性神经元添加自突触连接会导致更高的爆发频率。通过向高连接度的兴奋性神经元添加自突触，可以降低诱导爆发所需的自突触数量。这些结果表明自突触连接在控制哺乳动物大脑不同皮质和皮质下区域的网络范围爆发中起作用。此外，它们为研究结构可控性的动态神经生理学相关性开辟了新的途径。
