Function of the thalamo-cortical pathway in sensory-guided behaviour

丘脑是大脑核心的一个重要的“通讯中枢”。几乎所有来自感官的信号在到达大脑皮层的途中都要经过丘脑。丘脑对大脑皮层不同部分之间的交流也至关重要。因此，当丘脑受损时，例如中风，对患者的后果是毁灭性的。当我们清醒时，我们使用肌肉主动控制我们眼睛/手的感觉输入。因此，知觉是一个将运动控制与感觉输入相结合的主动过程。在麻醉状态下，这种运动控制是不活跃的。虽然我们知道很多关于丘脑在睡眠/麻醉的大脑中如何运作的知识，但我们仍然不知道当我们清醒并主动感知环境时，它是如何运作的。在这里，我们建议研究丘脑如何在清醒的、行为正常的动物中运作。幸运的是，在不同的哺乳动物物种和不同的神经系统中，丘脑回路非常相似，因此通过研究大鼠和小鼠，有可能洞察适用于人类健康的丘脑功能。大鼠和小鼠的胡须系统特别适合于这样的研究，因为有一种模块化的结构，与给定胡须有关的信号主要由丘脑中被称为“Barreloid”的离散区域处理。由于技术进步，现在可以在小鼠的胡须系统上进行实验，这在以前是不可能的。在这个项目中，我们将使用新的方法来研究当小鼠使用胡须来解决辨别任务(识别物体的位置)时，与胡须相关的丘脑是如何运作的。我们将首先研究丘脑神经元如何代表物体的位置，以及究竟是什么胡须运动引起了丘脑神经元的活动。最后，我们将研究在对象定位行为期间，丘脑神经元是如何受到大脑皮层反馈的调节的。

The thalamus is a critical 'communications hub' at the heart of the brain. Almost all signals from the senses pass through the thalamus on the way on their way to the cerebral cortex. Thalamus is also crucial for communication between different parts of the cerebral cortex. Thus, when thalamus is damaged, for example by stroke, the consequences for the patient are devastating.When we are awake, we actively control the sensory input to our eyes/hands using our muscles. Perception is thus an active process that integrates motor control with sensory input. Under anaesthesia, this motor control is inactive. Although we know a lot about how thalamus operates in the sleeping/anaesthetised brain, we still do not understand how it functions when we are awake and actively sensing the environment.Here, we propose to investigate how thalamus operates in the awake, behaving animal. Fortunately, thalamic circuitry is remarkably similar in different mammalian species and across different neural systems, so it is possible to get insight into thalamic function that is applicable to human health by studying rats and mice. The whisker system of rats and mice is particularly well-suited to such research, since there is a modular structure whereby signals relating to a given whisker are primarily processed by discrete regions known, in thalamus, as 'barreloids'.Due to technological progress, it is now feasible to perform experiments on the whisker system of mice that were not previously possible. In this project, we will use the new methods to study how the whisker-related thalamus operates when mice use their whiskers to solve a discrimination task (identifying the location of an object). We will first investigate how thalamic neurons represent object location and exactly what whisker movements it is that evoke activity in thalamic neurons. Finally, we will study how, during object localisation behaviour, thalamic neurons are modulated by feedback from the cerebral cortex.