The origins of neuronal correlations in cerebral cortex

项目摘要 在这里，我们建议使用协同混合来彻底描述皮层中成对相关性的起源 实验方法学、行为学和计算学。我们将阐明 正常化的机械基础，并测试我们的假设，即皮层成对相关性的变化 和其他信号来自于正在进行的皮层计算。在目标1中，我们将从神经元群体中记录 中颞视觉区的训练，表现猴子来测试假设，成对的尖峰 相关性，伽马振荡和视觉刺激开始时的瞬态响应部分地来自于 使神经元反应正常化的电路的动力学。这些测试需要精确的测量 这在老鼠身上是不可行的。相反，目标2和目标3中的实验解决了不可行的问题 在猴子身上。在目标2中，我们将通过使用双光子激光和双光子激光来探索小鼠视觉皮层的可及性。 扫描显微镜和多电极阵列，以全面测量 V1神经元群体的标准化和成对相关性，并测量 大脑皮层会影响这种关系最后，在目标3中，我们将确定特定细胞类别的贡献 小鼠V1的标准化和成对相关性。我们记录锥体神经元的活动， 三个最彻底的特点类皮质中间神经元（VIP，SST和PV）在正常化。我们 然后将分别操纵这些细胞类的活动，以揭示比例变化的作用， 兴奋和抑制在驱动正常化中发挥作用。通过这种方式，我们将确定这些神经元所起的作用， 改变神经元兴奋池中的成对相关性。所有三个目标的结果将是并列的 一起使用一个新的家庭的动态，经常性的电路模型的规范化，以形式化的假设， 标准化施加成对相关性和其他活动特征，并将使用实验数据来 约束和完善这些模型。

Project Summary Here, we propose to thoroughly characterize the origins of pairwise correlations in cortex using a synergistic mix of experimental methodologies, behavior, and computation in mice and macaques. We will elucidate the mechanistic underpinnings of normalization and test our hypothesis that changes in cortical pairwise correlations and other signature arise from ongoing cortical computations. In Aim 1 we will record from populations of neurons in the middle temporal visual area of trained, behaving monkeys to test the hypothesis that pairwise spike correlations, gamma oscillation and transient responses at the onset of visual stimuli arise in part from the dynamics of the circuits that normalize neuronal responses. These tests require measurements with a precision that is not feasible in mice. Conversely, the experiments in Aim 2 and 3 address questions that are not feasible in monkeys. In Aim 2 we will exploit the accessibility of mouse visual cortex by using both two-photon laser scanning microscopy and multielectrode arrays to comprehensively measure the relationship between normalization and pairwise correlations in populations of V1 neurons and measure how spatial separation within cerebral cortex affects that relationship. Finally, in Aim 3 we will establish the contributions of specific cell classes to normalization and pairwise correlations in mouse V1. We record the activity of pyramidal neurons and the three most thoroughly characterized classes of cortical interneuron (VIP, SST and PV) during normalization. We will then separately manipulate the activity of these cells classes to revealing the role that changes to the ratio of excitation and inhibition play in driving normalization. In this way, we will establish the role these neurons play in changing pairwise correlations within the excitatory pool of neurons. Results from all three Aims will be tied together using a new family of dynamic, recurrent circuit models of normalization to formalize the hypothesis that normalization imposes pairwise correlations and other activity signatures, and will use experimental data to constrain and refine these models.