DYNAMIC NEURAL ORGANIZATION IN NEOCORTEX

本研究的长期目标是了解新皮质中的局部群体相互作用，这是正常皮质功能和神经系统疾病（如癫痫）的重要过程。 我们的方法是检查的时空模式和细胞特性的人口活动的内在皮层电路。 我们假设，在新皮层的群体激活的一个基本形式是动态组织的多神经元合奏。 在我们以前的研究中，我们发现了一个局部的共激活在成人皮层切片，这是相关的活动模式在皮层。 这种共激活是动态组织的，具有低密度尖峰的全或无群体事件。 它可以由适当的刺激诱发，也可以在7 - 10 Hz振荡期间作为传播激活自发发生。 本研究将利用电压敏感染料成像和电生理方法进一步研究这一皮层群体事件的时空动态和神经元活动。 有四个具体目标。 目的1将研究能引起这种活动或与之相互作用的适当刺激模式，并探索这种活动是否能普遍发生在不同的皮层区域。 目标2将研究维持这种共激活的网络和细胞机制。 目的3将研究这种活动的传播和与皮质柱状组织的相互作用。 目的4将研究这个动态组织的群体事件中的神经元活动。本研究将增加我们对正常和病理条件下与输入模式相关的皮层群体活动和皮层内在活动的认识。

The long-term objective of this study is to understand the local population interactions in neocortex, an important process for both normal cortical functioning and for neurological disorders such as epilepsy. Our approach is to examine the spatio-temporal patterns and cellular properties of population activity in intrinsic cortical circuits. We hypothesize that one basic form of population activation in neocortex is the dynamically organized multi-neuronal ensemble. In our previous study we found a local co-activation in adult cortical slices which is related to the activity patterns in the cortex. This kind of co- activation is dynamically organized, all-or-none population event with an asynchronized, low density of spikes. It could be evoked by a proper stimulation or spontaneously occurred as a propagating activation during 7 to 10 Hz oscillations. This proposal will utilize voltage-sensitive dye imaging and electrophysiological methods to further study the spatio-temporal dynamics and neuronal activities of this cortical population event. There are four specific aims. Aim 1 will examine the proper stimulation patterns which can evoke or interact with this activity, and explore whether this activity can commonly occur in different cortical areas. Aim 2 will study the network and cellular mechanisms which sustain this co-activation. Aim 3 will study propagation of this activity and the interactions with the cortical columnar organization. Aim 4 will study the neuronal activity within this dynamically organized population event. This study will increase our knowledge about the cortical population activities related to the input pattern and intrinsic activities in cortex during normal and pathological conditions.