Visual signals in auditory midbrain

描述（由申请人提供）：我们所看到的帮助我们解释我们所听到的。整合视觉和听觉信息是人类行为的一个基本方面。视觉听觉整合障碍影响人类健康的许多方面，从沟通和语言到复杂环境中的注意力和运动。然而，这种能力的神经基础还没有被很好地理解。先前对仓鸮的研究主要集中在视觉信息如何被用来校准听觉空间的表征，并暗示下丘参与了这一过程。然而，我们对灵长类动物的这一区域知之甚少。恒河猴具有与人类非常相似的视觉和听觉系统，是研究视觉-听觉整合神经机制的优秀动物模型。人类和猴子的视觉-听觉整合与仓鸮不同，因为灵长类动物可以移动眼睛，而仓鸮却不能。因此，灵长类视听觉整合需要三个信号：视觉、听觉和眼睛位置信号。人们早就知道灵长类动物的IC包含听觉信息，我们最近也发现它包含眼睛位置信息（Groh et al., Neuron, 2001）。在这里，我们转向这个结构中的视觉信息。我们最近在清醒猴子的内窥镜中发现了强大的视觉反应。在本提案中，我们试图研究这些视觉反应的特性以及它们如何与该大脑区域的听觉和眼睛位置信息相关。具体来说，我们的目标是(1)表征视觉反应特性（目标1），(2)确定这些视觉反应的参考框架（目标2），并确定IC神经元如何对视觉和听觉联合刺激做出反应，特别是当这些刺激之间的空间差异产生腹语影响/后效时（目标3）。本文研究的视觉对听觉加工的影响机制涉及多种涉及视觉和听觉成分的疾病，如阅读障碍和自闭症。这些实验将有助于更好地理解听觉通路中视觉-听觉整合的皮层下机制，并可能最终导致治疗方案，以帮助改善这些疾病患者的缺陷。

DESCRIPTION (provided by applicant): What we see helps us interpret what we hear. Integrating visual and auditory information is a fundamental aspect of human behavior. Impairments in visual-auditory integration impact numerous aspects of human health, ranging from communication and language to attention and movements in a complicated environment. However, the neural basis of this ability is not well understood. Previous work in barn owls has focused on how the visual information is used to calibrate the representation of auditory space, and has implicated the inferior colliculus in this process. However, little is known about this area in primates. Rhesus monkeys have visual and auditory systems that are quite similar to humans, and serve as an excellent animal model for studying the neural mechanisms underlying visual-auditory integration. Visual-auditory integration in humans and monkeys is different from barn owls because primates can move their eyes whereas barn owls cannot. Thus, primate visual auditory integration requires three signals: visual, auditory, and eye position signals. It has long been known that the primate IC contains auditory information, and we have recently shown that it contains eye position information (Groh et al., Neuron, 2001). Here, we turn to visual information in this structure. We have recently discovered robust visual responses in the IC of awake monkeys. In this proposal, we seek to study the properties of these visual responses and how they relate to auditory and eye position information in this brain region. Specifically, we aim to (1) characterize the visual response properties (Aim 1), (2) determine the frame of reference of these visual responses (Aim 2), and determine how IC neurons respond to combined visual and auditory stimuli, especially when a spatial disparity between these stimuli produces a ventriloquism affect/aftereffect (Aim 3). The mechanisms of visual influence over auditory processing investigated here bear on a variety of disorders involving both visual and auditory components, such as dyslexia and autism. These experiments will yield a greater understanding of subcortical mechanisms for visual-auditory integration within the auditory pathway and may ultimately lead to treatment regimens to help ameliorate the deficits experienced by patients with these disorders.