CRCNS: Physiological and Computational Approaches to Understanding Neuronal Synch

描述(由申请人提供)：当神经元一起放电时，更有效地传递信息。即使同步性略有增加，下游神经元的放电频率也会发生很大变化。同步活动，尤其是振荡同步，在许多脑网络中被观察到，并被认为在刺激的表征、活动的传播和计算中发挥着重要作用。同步性的改变，特别是在伽马频率范围内，最近被认为与一些认知障碍的病因有关，最明显的是精神分裂症。然而，事实证明，将这些变化与突触和细胞属性的变化同步联系起来很困难。在这里，我们描述的实验旨在检验一种新的产生同步振荡的机制，我们称之为随机同步。最近，人们对描述通过非周期的、部分相关的、有噪声的输入来同步振荡神经元的理论工作产生了浓厚的兴趣。我们已经在实验上证明，这种输入可以在非耦合神经元(嗅球二尖瓣细胞)中产生振荡同步，并提出这种机制可能解释了嗅球快速(伽马频率)同步振荡的发展。在这里，我们提出了更广泛的噪声诱导神经元同步的进一步的理论和实验研究。具体地说，我们建议分析噪声诱导的同步对噪声输入的性质和振荡器的动力学的依赖关系。通过实验和理论相结合的研究，我们将确定哪些通道类型对该机制的同步发展最关键。我们还建议研究噪声诱导的同步和连接诱导的同步的相互作用，因为在许多情况下，这两种现象都可能涉及跨大脑网络的同步活动模式的产生。通过探索这一新的伽马振荡机制，我们希望更好地理解细胞和电路级属性的改变如何干扰正常伽马振荡的发展。这些工作将对理解精神分裂症等与伽马活动改变相关的疾病具有重要意义。

DESCRIPTION (provided by applicant): Neurons convey messages more effectively when firing together. Even modest increases in synchronization result in large changes in firing rate for downstream neurons. Synchronous activity, especially oscillatory synchrony, is observed in many brain networks and is thought to play an important role in representation of stimuli, propagation of activity and computation. Alterations of synchrony, especially in the gamma frequency range, have recently been implicated in the etiology in a number of cognitive disorders, most notably schizophrenia. However, linking the alterations in synchrony with the alterations in synaptic and cellular properties has proven difficult. Here we describe experiments designed to examine a novel mechanism for the generation of synchronous oscillations which we call stochastic synchrony. Recently, substantial interest has arisen in theoretical work describing synchronization of oscillating neurons by aperiodic, partially correlated, noisy inputs. We have shown experimentally that such inputs can generate oscillatory synchrony in uncoupled neurons (olfactory bulb mitral cells) and have proposed that this mechanism may account for the development of fast (gamma frequency) synchronous oscillations in the olfactory bulb. Here we propose further theoretical and experimental investigations of noise-induced synchronization in neurons more generally. Specifically, we propose to analyze the dependence of noise-induced synchronization on properties of the noisy inputs and on the dynamics of the oscillators. By combined experimental and theoretical investigation, we will determine which channel types are most critical for the development of synchrony by this mechanism. We also propose to study the interaction of noise-induced and connectivity-induced synchronization, as in many cases these two phenomena are likely to both be involved in generating patterns of synchronous activity across brain networks. By exploring this novel mechanism of gamma oscillations we hope to better understand how alteration of cellular and circuit-level properties can interfere with the development of normal gamma oscillations. Such work will have importance for understanding disorders such as schizophrenia, which are associated with altered gamma activity.