Effects of Hindlimb Inputs on the Activity of Vestibular Nucleus Neurons

描述（由申请人提供）：尽管前庭系统在发出头部在空间中的运动信号方面具有极高的灵敏度，但是需要关于身体在空间中的取向的附加信息来控制平衡。前庭传入信息在本体感受和视觉信息的背景下被解释和成形。为了达到稳定的平衡，很可能前庭和腿部本体感受传入信号的整合是至关重要的，因为腿部通常作为与地面和肢体位置形状前庭脊髓反应的唯一接口。然而，几乎没有什么是已知的肢体传入信号与前庭传入信号在中枢前庭通路。主 本应用的目的是确定体感肢体输入对活动的影响 前庭神经核（VN）神经元。提出了三个具体目标。在第一个具体的目标，我们将描述后肢运动如何影响VN神经元的响应，以激活肾上腺素受体的头部旋转。我们还将确定哪个VN神经元亚类对后肢运动敏感。在第二个具体的目标，我们将确定VN神经元之间的自我产生的后肢运动和外部施加的运动区分。在第三个具体的目标，我们将确定是否后肢运动信号VN神经元放大后，失去的前庭输入，并取代失去的前庭信号。这些实验有望促进对中枢前庭通路中肢体体感输入处理的理解，并可能最终导致前庭神经病患者的新疗法。

DESCRIPTION (provided by applicant): Although the vestibular system has exquisite sensitivity in signaling head movement in space, additional information about the orientation of the body in space is needed for the control of balance. Vestibular afferent information is interpreted and shaped in the context of proprioceptive and visual information. To achieve stable balance, it is likely that integration of vestibular and leg proprioceptive afferent signalsis critical, since the legs typically serve as the sole interface with the ground and limb position shapes vestibulospinal responses. However, virtually nothing is known about how limb afferent signals are integrated with vestibular afferent signals in central vestibular pathways. The primary goal of this application is to determine the influence of somatosensory limb inputs on the activity of vestibular nucleus (VN) neurons. Three specific aims are proposed. In the first specific aim, we will characterize how hindlimb movements affect the responses of VN neurons to rotations of the head that activate labyrinthine receptors. We will additionally determine which subclass of VN neurons is sensitive to hindlimb movement. In the second specific aim, we will determine whether VN neurons differentiate between self-generated hindlimb movement and externally applied movement. In the third specific aim, we will determine whether hindlimb movement signals to VN neurons are amplified following loss of labyrinthine inputs, and substitute for the lost vestibular signals. These experiments are expected to advance understanding regarding the processing of limb somatosensory inputs in central vestibular pathways and may ultimately lead to novel therapies for vestibulopathic patients.