Hysteresis and slow drift in abducens unit activity.
Hysteresis and slow drift in abducens unit activity.
复制标题
外展肌单位活动的滞后和缓慢漂移。
DOI：
10.1152/jn.1986.55.5.1044
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发表时间：
1986
影响因子：
2.5
通讯作者：
Robinson,DA
中科院分区：
文献类型：
--
作者：
Goldstein,HP;Robinson,DA
两只受过训练的猴子对一个小的视觉目标进行扫视运动。活动的39个孤立的外展神经单位，推测是运动神经元或外展神经核间神经元，记录在这些眼球运动。在校准试验之后，测试试验重复地引起从左侧或右侧到主位置的20度水平扫视。平均而言，在主要位置的稳态放电率取决于扫视的方向。对于其中神经元在扫视期间表现出活动爆发的扫视（在扫视期间），稳态放电率通常高于在扫视期间表现出活动暂停的那些扫视（在扫视期间）。对于单元群体，该滞后测量为5.4个尖峰/s，其可以与97个尖峰/s的平均初级位置速率进行比较。单个单元的平均滞后范围为-2.1至18.5尖峰/秒。在相同方向上的相等扫视后，在相同位置（主要）结束的稳态放电率随时间缓慢变化。在所有装置中，变异性（标准差）范围为0.5 - 11.8个峰值/s，平均值为4.7个峰值/s。此外，对于任何一个单元，在扫视之后的变化通常与在非扫视之后的变化相关。许多人怀疑的滞后现象确实存在。幸运的是，它是足够小的，5.5%的典型的一级位置率，它可以忽略不计的许多目的。然而，它提出了一个有趣的理论问题，即眼科系统如何补偿滞后。背景速率缓慢变化的最简单解释是共收缩噪声：所有外展神经元的缓慢波动，因此这些变化不会导致眼睛位置的波动。
Two trained monkeys made saccadic eye movements to a small visual target. The activity of 39 isolated abducens units, presumed to be motoneurons or abducens internuclear neurons, was recorded in relation to these eye movements. After a calibration trial, a test trial repeatedly elicited 20 degrees horizontal saccades to primary position from either the left or right. On average, the steady-state firing rate at primary position depended on the direction of the saccade. For saccades where the neuron showed a burst in activity during the saccade (on-saccades) the steady-state firing rates were usually higher than for those saccades that showed a pause in activity during the saccade (off-saccades). For the population of units this hysteresis measured 5.4 spikes/s, which may be compared with an average primary-position rate of 97 spikes/s. The average hysteresis for individual units ranged from -2.1 to 18.5 spikes/s. The steady-state firing rate after equal saccades in the same direction and ending at the same position (primary) varied slowly over time. Across all units the variability (standard deviation) ranged from 0.5 to 11.8 spikes/s with a mean of 4.7 spikes/s. Furthermore, for any one unit the variations following on-saccades generally correlated with the variations following the off-saccades. Hysteresis, doubted by many, does exist. Fortunately, it is small enough, 5.5% of typical primary-position rate, that it can be neglected for many purposes. Nevertheless, it poses the interesting theoretical question of how the oculomotor system compensates for hysteresis. The simplest explanation of slow variations in background rate is cocontractive noise: a slow fluctuation in all abducens neurons so that these variations do not result in fluctuations of eye position.