Robust network oscillations during mammalian respiratory rhythm generation driven by synaptic dynamics
Robust network oscillations during mammalian respiratory rhythm generation driven by synaptic dynamics
复制标题
DOI：
10.1073/pnas.1421997112
复制
发表时间：
2015-08-04
影响因子：
11.1
通讯作者：
Holcman, David
中科院分区：
文献类型：
--
作者：
Guerrier, Claire;Hayes, John A.;Holcman, David
突触动力学如何在神经元网络中产生同步振荡？我们在preBotzinger复合体（preBotC）中解决了这个问题，这是一种脑干神经网络，在哺乳动物中具有强大但不稳定的灵感。preBotC由几百个神经元组成，这些神经元交替爆发活动和沉默期，但这种重要节律的机制仍然难以捉摸。使用一种计算方法来模拟随机连接的神经元网络，依赖于短期突触促进（SF）和抑郁症（SD），我们表明，突触波动可以启动人口活动，通过经常性的兴奋。我们还表明，一个两步SD过程允许在网络中的活动同步（突发），并产生人口不应期（沉默）。该模型进行了验证，对一系列的实验条件，概括了几个过程的preBotC可能会遇到的。与建模假设相一致，我们揭示，通过电生理记录，SF/SD可以发生在影响节律性群体活动的时间尺度上的preBotC突触。我们的结论是，在一个随机连接的网络的非确定性神经元尖峰和动态突触强度是足够的，以引起定期的类似的节奏网络的活动和不稳定性，这可能发挥重要作用，在哺乳动物的呼吸和其他协调的运动活动的节奏。
How might synaptic dynamics generate synchronous oscillations in neuronal networks? We address this question in the preBotzinger complex (preBotC), a brainstem neural network that paces robust, yet labile, inspiration in mammals. The preBotC is composed of a few hundred neurons that alternate bursting activity with silent periods, but the mechanism underlying this vital rhythm remains elusive. Using a computational approach to model a randomly connected neuronal network that relies on short-term synaptic facilitation (SF) and depression (SD), we show that synaptic fluctuations can initiate population activities through recurrent excitation. We also show that a two-step SD process allows activity in the network to synchronize (bursts) and generate a population refractory period (silence). The model was validated against an array of experimental conditions, which recapitulate several processes the preBotC may experience. Consistent with the modeling assumptions, we reveal, by electrophysiological recordings, that SF/SD can occur at preBotC synapses on timescales that influence rhythmic population activity. We conclude that nondeterministic neuronal spiking and dynamic synaptic strengths in a randomly connected network are sufficient to give rise to regular respiratory-like rhythmic network activity and lability, which may play an important role in generating the rhythm for breathing and other coordinated motor activities in mammals.