Effects of random external background stimulation on network synaptic stability after tetanization - A modeling study
Effects of random external background stimulation on network synaptic stability after tetanization - A modeling study
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DOI：
10.1385/ni:3:3:263
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发表时间：
2005-01-01
期刊：
影响因子：
3
通讯作者：
Potter, SM
中科院分区：
文献类型：
--
作者：
Chao, ZC;Bakkum, DJ;Potter, SM
我们构建了一个模拟发放神经网络模型，研究随机背景刺激对网络活动模式动力学和破伤风诱导的网络可塑性的影响。模拟模型是一个具有尖峰时间依赖性可塑性（STDP）和频率依赖性突触抑制的“泄漏整合和激发”（LIF）神经模型。自发和诱发的活动模式进行了比较，与活的神经元网络上培养的多电极阵列。为了帮助在我们的模拟模型中可视化活动模式和可塑性，我们引入了称为活动中心（CA）和权重中心（CW）的新群体度量，分别描述网络范围内的放电活动和网络范围内的突触强度的时空动态。没有随机背景刺激，网络突触权重不稳定，并且在强直化后经常漂移。相反，在随机背景刺激下，网络突触权重在强直化后立即保持接近其值。模拟结果表明，强直化对网络突触权重的影响很难控制，因为动作电位的持续同步自发爆发，或称“弹幕”。随机背景刺激通过减少自发性弹幕的数量和影响来帮助维持强直后网络突触的稳定性。我们使用我们的模拟网络来模拟正在进行的神经活动，外部刺激和可塑性之间的相互作用，并指导我们选择混合神经机器人系统或“hybrots”中的适应行为的感觉-运动映射。"
We constructed a simulated spiking neural network model to investigate the effects of random background stimulation on the dynamics of network activity patterns and tetanus induced network plasticity. The simulated model was a "leaky integrate-and-fire" (LIF) neural model with spike-timing-dependent plasticity (STDP) and frequency-dependent synaptic depression. Spontaneous and evoked activity patterns were compared with those of living neuronal networks cultured on multi-electrode arrays. To help visualize activity patterns and plasticity in our simulated model, we introduced new population measures called Center of Activity (CA) and Center of Weights (CW) to describe the spatio-temporal dynamics of network-wide firing activity and network-wide synaptic strength, respectively, Without random background stimulation, the network synaptic weights were unstable and often drifted after tetanization. In contrast, with random background stimulation, the network synaptic weights remained close to their values immediately after tetanization. The simulation suggest that the effects of tetanization on network synaptic weights were difficult to control because of ongoing synchronized spontaneous bursts of actions potentials, or "barrages." Random background stimulation helped maintain network synaptic stability after tetanization by reducing the number and thus the influence of spontaneous barrages. We used our simulated network to model the interaction between ongoing neural activity, external stimulation and plasticity, and to guide our choice of sensory-motor mappings for adaptive behavior in hybrid neural-robotic systems or "hybrots."