Modulation of Neural Representation & Perception by Thalamocortical Alpha Rhythm

描述（由申请人提供）：了解大脑如何动态地改变其组织和处理，以满足感官知觉的需要是健康和疾病的一个关键问题。大鼠触须（胡须）感觉系统是探索这些问题的绝佳模型，因为它是一种高分辨率感觉系统，在“桶”皮质中，关于细胞类型和层特异性处理有很多已知信息。阿尔法节律是一种常见的大脑振荡状态，最近被认为与调节选择性注意力有关。我将测试与alpha相关的三个假设。首先，我将测试的预测（“增益调制”的假设），丘脑皮层7-12赫兹α振荡降低幅度的感觉诱发反应在假定的兴奋性和抑制性第四层神经元。其次，我将测试预测（“感觉调制”假说），增加阿尔法功率预测阈值水平刺激的检测概率下降。第三，我将测试的预测（“感觉部署”假说），在高度训练的动物阿尔法功率调制作为一个功能的线索注意，效果不会被观察到在没有线索期间或当线索不预测奖励的可能性。我将测试这些假设在头贴大鼠训练检测离散和良好控制的触须偏转。我将在任务执行过程中使用16通道层流记录来记录神经振荡以及兴奋性和抑制性单个单元活动。最终，对动物模型中节律活动的更透彻理解将导致对人类振荡的更好理解。在该模型系统中探索的α节律被认为与人类的类似生理起源有直接相关性。这一研究方向有能力理解许多疾病背后的机制，包括癫痫，其中这种动力学被改变。

DESCRIPTION (provided by applicant): Understanding how the brain dynamically alters its organization and processing to meet the needs of sensory perception is a crucial question in health and disease. The rat vibrissa (whisker) sensory system is an excellent model in which to explore these issues, as it is a high-resolution sensory system where a great deal is known, in the 'barrel' cortex, about cell type and layer-specific processing. Alpha rhythm is a commonly observed oscillatory brain state that has recently been linked to modulating selective attention. I will test 3 hypotheses related to alpha. First, I will test the prediction (the 'gain modulation' hypothesis), that thalamocortical 7-12 Hz alpha oscillations reduce the amplitude of sensory evoked responses in putative excitatory and inhibitory layer IV neurons. Second, I will test the prediction (the 'sensory modulation' hypothesis) that increased alpha power predicts decreased detection probability for threshold-level stimuli. Third, I will test the prediction (the 'sensory deployment' hypothesis) that in highly trained animals alpha power is modulated as a function of cued attention, effects that will not be observed in no cue periods or when the cue does not predict reward possibility. I will test these hypotheses in head-posted rats trained to detect discrete and well-controlled vibrissa deflections. I will record neural oscillations and excitatory and inhibitory single unit activity using 16-channel laminar recordings during task performance. Ultimately, a more thorough understanding of rhythmic activity in animal models will lead to a better understanding of oscillations in humans. The alpha rhythm explored in this model system is believed to have direct correlates with similar physiological origins in humans. This direction of research has the power of understanding mechanisms behind many disorders, including epilepsy, where such dynamics are altered.