ENSEMBLE NEURAL CODING OF PLACE AND DIRECTION IN ZERO-G

描述：(改编自申请人的摘要。)近期 神经生理和行为实验有力地表明 快速有效的空间定位能力是基于 主要是关于一组高阶神经元之间的相互作用 传输空间位置的表示，以及广泛的网络 使用前庭的新皮质和皮质下神经元， 用于计算和传输信号的角速度信息 反映动物头部方位的方位分量， 相对于惯性参考框架。这样的系统在理想情况下是 适用于计算 地球环境，首先是因为它使太空能够 内部表示并经济地存储为一组里程碑式的- 向量，第二，因为它允许轨迹计算 通过向量减法来实现。后一种能力 允许快速计算新的、直接的轨迹到 期望的目标。显然，这个定位系统是 基于相对于局部引力的方位信息 菲尔德表明，问题可能在低重力或零重力下发展。 情况。目前关于神经实验室任务的提议旨在 利用自由行为啮齿动物的神经生理学实验 解决这个关键系统如何运行的问题，并 适应低重力条件。 在这个实验室开发的方法使同步 来自参与空间活动的大量神经元的记录 定位系统，并使相同的神经元集合能够 他们花了长达几周的时间学习。这项技术将 最大限度地提高相关神经生理学数据的数量 从少量啮齿动物(2-4只)获得。调查人员 实事求是地期望能够获得良好的隔离单元 多达1000个新皮质、丘脑和顶盖的录音 一次任务过程中的神经元，并研究集合 在任何给定的记录实验中50-150个细胞的相互作用。他们 还建议在以下方面与其他研究小组合作 使用相同的技术来解决其他重要问题 与空间飞行有关的神经生理学问题，包括 运动控制和感觉-运动整合的可能变化， 睡眠-唤醒周期和自主控制。

DESCRIPTION: (Adapted from the Applicant's Abstract.) Recent neurophysiological and behavioral experiments strongly suggest that the capacity for rapid and effective spatial orientation is based primarily on the interaction between a set of high-order neurons that transmit a representation of spatial location, and an extensive network of neocortical and subcortical neurons which use vestibular, angular-velocity information to compute and transmit a signal reflecting the azimuthal component of the animal's head orientation, relative to an inertial reference framework. Such a system is ideally suited for the computation of relevant behavioral trajectories in an earth-bound environment, first because it enables space to be internally represented and stored economically as a set of landmark- vectors, and second, because it enables the trajectory computation to be carried out by vector subtraction. The latter capacity permits the rapid calculation of novel, direct trajectories to a desired target. Clearly, the fact that this orientation system is based on azimuthal information with respect to the local gravitational field suggests that problems may develop in low or zero-gravity situations. The present proposal for the NeuroLab mission aims to use neurophysiological experiments in freely behaving rodents to address the question of how this crucial system performs and adapts to low gravity conditions. Methods developed in this laboratory have enabled the simultaneous recording from large numbers of neurons involved in the spatial orientation system and which enable the same neuronal ensembles to be studied over periods of up to several weeks. This technology will maximize the amount of relevant neurophysiological data that can be obtained from a small number of rodents (2-4). The investigators realistically expect to be able to obtain well isolated unit recordings from as many as 1000 neocortical, thalamic, and tectal neurons over the course of a single mission, and to study the ensemble interactions of 50-150 cells in any given recording experiment. They also propose to assist and collaborate with other research groups in employing the same technology to address other important neurophysiological questions of relevance to space flight, including possible changes in motor control and sensori-motor integration, sleep-waking cycles, and autonomic control.