Eye and head contributions to gaze stability

描述（由申请人提供）：眼睛和头部反射对于始终保持空间中的凝视方向是必不可少的，使得视网膜图像稳定。虽然鸽子（像所有侧眼动物一样）的VOR被报道为代偿不足，但在飞行等自然行为中，鸟类必须能够保持凝视稳定，可能使用涉及VCR，CCR和惯性（头部反应）的协调头部运动来保持稳定的凝视。此外，以前已经提出了基于放电动力学的前庭传入的不同功能作用。已知不规则放电传入神经对阳极电流敏感，而阳极电流对VOR角几乎没有影响。推测不规则传入可能在头颈部运动反应的功能通路中起更重要的作用。在目前提出的一系列实验中，将首先确定鸽子在旋转和线性运动期间的三维凝视稳定性，检查眼睛和头部的相对贡献。其次，将确定改变不规则发射传入的输入对凝视稳定性的影响。对于这两个目标，感兴趣的定量测量将包括空间中的眼睛、空间中的头部和头部中的眼睛。

DESCRIPTION (provided by applicant): Eye and head reflexes are essential in maintaining the orientation of gaze in space at all times such that retinal images are stabilized. Although the VOR in pigeons (like all lateral-eyed animals) has been reported as undercompensatory, during natural behaviors such as flight, birds must be able to maintain gaze stability, perhaps using concerted head movement involving the VCR, CCR and inertia (head responses) to maintain steady gaze. In addition, different functional roles for vestibular afferents based on discharge dynamics have been previously proposed. Irregularly firing afferents are known to be sensitive to anodal galvanic currents which seem to have little effect upon the angular VOR. It is postulated that the irregular afferents may play a more significant role in the functional pathways of head and neck responses to motion. In the present proposed series of experiments, three-dimensional gaze stability will first be determined in pigeons during rotational and linear motion, examining the relative contributions of the eye and head. Second, the effects of altering the input from irregularly firing afferents upon gaze stability will be determined. For both objectives, quantitative measures of interest will include eye-in-space, head-in-space, and eye-in-head.