Superior colliculus participation in rat vibrissa sensorimotor loops

描述（由申请人提供）：解释复杂的感官刺激对正常的人体功能至关重要。许多疾病和障碍，包括自闭症和多动症，涉及感觉缺陷或异常。这些通常包括对不同类型的简单和复杂刺激的过度反应和低反应。上级丘参与感知听觉、视觉和躯体感觉刺激，被认为参与处理复杂的刺激并适当地引导注意力。虽然涉及上级丘的视觉通路的研究已经取得了有前途的结果与感觉运动处理和注意力，这些发现可能是有限的，集中在视觉模态。为了充分理解复杂刺激引起的感觉运动处理，我们必须探索其他感觉方式。本研究以大鼠触须系统为模型，探讨上级丘控制的定向和注意功能与躯体感觉的关系。我们将研究一个假定的闭合感觉运动回路，它将感觉信息转化为运动输出，目的是阐明一般的感觉运动转换，从而产生对单感官和多感官刺激的反应。我也将测试如何调节警觉或唤醒状态的机制可能会影响这种感觉运动处理。具体目的一：验证顶面神经元是触须感觉运动回路中的Transformer的假设。我预测，tectofacial神经元接受体感输入，可以驱动持续放电的面部神经元。为了测试这一点，我将调查的响应特性和相关的生物物理特性，确定tectofacial神经元，使用在体内和体外制剂。具体目标二：验证脑干胆碱能系统的激活增强触须-顶盖感觉运动回路的运作这一假设。我预测，胆碱能系统增加的反应tectofacial神经元的体感刺激，并增加其能力，以驱动下游运动神经元。我将测试这些预测激活胆碱能脑干区域在体内，并通过应用胆碱能药物在体内和体外。我们正在研究上级丘在对躯体感觉刺激作出适当反应中的作用。这项研究将有助于我们理解人们如何解释和响应简单（即针刺）和复杂（即来自父母的拥抱）的刺激。

DESCRIPTION (provided by applicant): Interpreting complex sensory stimuli is critical for normal human functioning. Many diseases and disorders, including autism and hyperactivity, involve sensory deficits or abnormalities. These commonly include hyper- and hypo-responsiveness to different types of simple and complex stimuli. The superior colliculus, which is involved in sensing auditory, visual, and somatosensory stimuli, is thought to participate in processing complex stimuli and directing attention appropriately. While studies of visual pathways involving the superior colliculus have yielded promising results relating to sensorimotor processing and attention, these findings may be limited by focusing on the visual modality. In order to fully understand the sensorimotor processing occurring in response to complex stimuli, we must explore other sensory modalities. This proposal will explore the orienting and attentive functions controlled by the superior colliculus in relation to somatosensation using the rat vibrissa system as a model. We will investigate a putative closed sensorimotor loop which transforms sensory information into motor output with the goal of elucidating general sensorimotor transformations which generate responses to mono- and multisensory stimuli. I will also test how mechanisms regulating states of vigilance or arousal may affect this sensorimotor processing. Specific Aim I: To test the hypothesis that the tectofacial neurons are the transformer in a vibrissa sensorimotor loop. I predict that tectofacial neurons receive somatosensory input and can drive sustained firing in facial neurons. To test this I will investigate the response properties and relevant biophysical properties of identified tectofacial neurons, using both in vivo and in vitro preparations. Specific Aim II: To test the hypothesis that activation of the brainstem cholinergic system enhances the operation of the vibrissa-tectal sensorimotor loop. I predict that the cholinergic system increases the responsiveness of tectofacial neurons to somatosensory stimuli, and increases their ability to drive downstream motoneurons. I will test these predictions by activating cholinergic brainstem regions in vivo and by applying cholinergic agents in vivo and in vitro. We are investigating the role of the superior colliculus in responding appropriately to somatosensory stimuli. This study will contribute to our understanding of how people interpret and respond to simple (i.e. a pin prick) and complex (i.e. a hug from a parent) stimuli.