Cortical mechanisms mediating visual function and behavior

项目摘要 来自感觉皮层的细胞内记录提供了一个了解突触输入的窗口， 单个皮层神经元的反应，但直到最近，这种强大的技术一直局限于 麻醉动物通过结合我们实验室的独特专业知识，我们开发了一种新颖的 技术，使我们能够进行，在常规的基础上，可靠的，全细胞的细胞内记录在原代 视觉皮层（V1）的清醒，行为猕猴。我们将联合收割机细胞内记录与一系列 伴随的测量提供了对神经元在其中的局部网络的状态的访问， 嵌入以及动物的内部状态。使用这些技术，我们可以访问 阈下（膜电位，代表输入）和阈上（尖峰，代表输出） 单个皮层神经元的反应，同时也利用视觉刺激的精确控制和 受试者的行为状态由行为灵长类动物提供。 我们在清醒的、行为正常的灵长类动物中进行细胞内记录的能力，为解决三个问题打开了大门。 关于介导视觉感知的回路水平机制的基本问题：（1）什么 是感觉皮质巨大神经变异性的本质、来源和行为后果 神经元，（2）内部状态波动对这种可变性的贡献是什么，（3）什么电路模型 能解释自发反应和诱发反应中观察到的神经变异吗 为了解决这些问题，在目标1中，我们将研究子和子之间的定量关系。 阈上活动在自发和刺激诱发的反应在V1的固定猴。这 将使我们能够测试以前在麻醉动物身上发现的普遍性。在目标2中，我们将研究 单个V1神经元的活动与猴子的感知决策之间的关系， 从事一项要求很高的视觉检测任务。具体来说，我们将研究如何在阈下和阈上 通过改变刺激所处的注意力和动机状态， 提出了最后，在目标3中，我们将测试一组新的电路模型，这些模型可以解释我们观察到的结果 并指导未来的实验。

Project Summary Intracellular recording from sensory cortex provides a window into the synaptic inputs that shape spiking responses of individual cortical neurons, but until recently, this powerful technique has been limited to anesthetized animals. By combining the unique expertise from our laboratories, we have developed a novel technique that allow us to conduct, on a routine basis, reliable, whole-cell intracellular recording in primary visual cortex (V1) of awake, behaving macaque monkeys. We combine intracellular recording with an array of concomitant measurements that provide access to the state of the local network in which the neuron is embedded as well as to the internal state of the animal. Using these techniques, we have access to both subthreshold (membrane potentials, representing input) and suprathreshold (spikes, representing output) responses of individual cortical neurons, while also utilizing the precise control of visual stimulation and the subject’s behavioral state afforded by behaving primates. Our ability to perform intracellular recording in awake, behaving primates opens the door to addressing three fundamental questions with respect to the circuit-level mechanisms that mediate visual perception: (1) what are the nature, sources, and behavioral consequences of the large neural variability of sensory cortical neurons, (2) what is the contribution of internal state fluctuations to this variability, (3) what circuit models can account for the observed neural variability during spontaneous and evoked responses? To address these questions, in Aim 1 we will study the quantitative relationship between sub- and suprathreshold activity during spontaneous and stimulus-evoked responses in V1 of fixating monkeys. This will allow us to test the generality of previous findings from anesthetized animals. In Aim 2, we will examine the relationship between the activity of single V1 neurons and perceptual decisions in monkeys that are engaged in a demanding visual detection task. Specifically, we will examine how sub- and suprathreshold responses are altered by changing the attentional and motivational states under which the stimulus is presented. Finally, in Aim 3 we will test a novel set of circuit models that can account for our observed results and guide future experiments.