Neural Mechanisms of Visual and Auditory Stimulus Selection

描述：了解注意力背后的细胞机制对于开发有效治疗影响注意力的许多精神和学习障碍至关重要。我们已经开发了谷仓猫头鹰的实验方案，使我们能够详细定量地研究注意力的一个基本组成部分--刺激选择的细胞基础。这项研究的目的是在神经元水平上分析自下而上(自动)和自上而下的刺激选择的特点，并阐明这些过程的机制。自下而上和自上而下的刺激选择的特性将在视顶盖中进行研究，视顶盖是一种已知的参与空间注意的结构。多个同时的感觉刺激对神经元反应的影响将被测量，因为竞争刺激的显著程度和位置是参数不同的。自上而下的信号(起源于前脑)，即偏向刺激选择将被微电刺激激活。最后，将通过电生理学和药理学失活实验来探索专门化胆碱能核和GABA能核在自下而上和自上而下刺激选择中的各自作用。大脑选择注意力刺激的机制尚不清楚。此外，胆碱能输入对大脑信息处理的影响还不清楚。许多衰弱的疾病(如精神分裂症、自闭症、多动症)包括刺激选择功能障碍，而其他疾病(如阿尔茨海默氏症、帕金森氏症、唐氏症)与胆碱能传递的调节失调有关。了解刺激选择的细胞机制和胆碱能回路的功能对于开发能够减轻或补救这些疾病的破坏性影响的治疗方法至关重要。

DESCRIPTION: Understanding the cellular mechanisms that underlie attention is crucial for developing effective treatments for the many psychiatric and learning disorders that affect attention. We have developed experimental protocols in the barn owl that allow us to study the cellular basis of a fundamental component of attention, stimulus selection, in quantitative detail. The aim of the proposed research is to analyze characteristics of bottom-up (automatic) and top-down stimulus selection at the neuronal level and to elucidate mechanisms that underlie these processes. The properties of bottom-up and top-down stimulus selection will be studied in the optic tectum, a structure known to be involved in spatial attention. The effects of multiple, simultaneous sensory stimuli on neuronal responses will be measured as the salience and location of competing stimuli are varied parametrically. Top-down signals (originating in the forebrain) that bias stimulus selection will be activated by electrical microstimulation. Finally, the respective roles of specialized cholinergic and GABAergic nuclei in bottom-up and top-down stimulus selection will be explored with electrophysiology and pharmacological inactivation experiments. The mechanisms by which the brain selects stimuli for attention are not known. In addition, the effects of cholinergic input on information processing in the brain are not understood. Many debilitating conditions (e.g., Schizophrenia, Autism, ADHD) include dysfunctions of stimulus selection, and others (e.g., Alzheimer's, Parkinson's, Down's) are associated with dysregulation of cholinergic transmission. An understanding of the cellular mechanisms of stimulus selection and the function of cholinergic circuits is crucial for developing treatments that can mitigate or remediate the devastating effects of these conditions.