两种等亮度不同运动图形刺激下的交替OKN眼动

等亮度彩色运动条纹产生视动震颤（ＯＫＮ）眼动反应揭示了ＯＫＮ眼动控制系统中存在颜色通道;而在两个相反方向运动的等亮度彩色运动条纹图象同时显示刺激时能引起交替的两个方向的ＯＫＮ跟踪眼动。故表明了在ＯＫＮ眼动控制系统中各个颜色通道交替地控制产生ＯＫＮ眼动反应。     

分眼刺激时家兔的交替OKN眼动跟踪特性

本工作用不同运动图形分别同时刺激家兔左右眼,通过检测正常及单侧前庭迷路损伤后家兔的ＯＫＮ反应,证明在这种刺激情况下,正常家兔的眼动反应为交替的ＯＫＮ反应,为进一步探讨交替ＯＫＮ的控制机制及控制部位建立了动物模型。     

经直接与间接通路的视动震颤(OKN)眼动反应

采用鼻向及颞光栅图形刺激猫的半侧视网膜,以探讨鼻侧半神网膜至视束核的视动震颤直接通路及颞侧半视网膜经皮层至ＮＯＴ的间接通路对ＯＫＮ眼动反应的神经控制特性。实验结果显示：高速度刺激的闭环ＯＫＮ反应及开环ＯＫＮ反应均对鼻向运动刺激有明显的方向选择性;半侧视网膜刺激时,鼻侧半视网膜的鼻向ＯＫＮ增益明显高于颞侧半视网膜的鼻向增益,说明猫的ＫＯＮ眼动反应以跟踪鼻向运动为主,并且这种对鼻向运动刺激选择性主要来     

家兔的开环及闭环视动震颤（OKN）研究

研究了家兔闭环及开环状态的ＯＫＮ反应。闭环时,ＯＫＮ眼动速度与刺激速度成正比,增益接近１。当固定受刺激眼形成开环状态时,ＯＫＮ眼动速度远大于刺激速度,增益可达１０２左右,说明ＯＫＮ系统是由运动跟踪的负反馈机制控制的;刺激范围缩小则眼动反应减弱,表明ＯＫＮ系统对运动信息具有空间总和作用;以视野中不同高度的局部刺激时,发现视网膜中央视带比周边部对ＯＫＮ刺激的敏感性高;单光点刺激视带中央可诱发出清楚的ＯＫＮ反应,这为临床上应用ＯＫＮ客观测定视网膜功能和运动感知提供了可能性。     

家兔视动震颤(OKN)眼动反应的方向特性

采用两维方向上运动的光栅作为刺激并以电磁感应眼动测量方法对家兔ＯＫＮ方向特性进行研究。结果表明：水平单一方向运动的图形刺激时,只有鼻向刺激引起ＯＫＮ反应,且ＯＫＮ反应的慢相方向接近于刺激方向,说明水平刺激时,家兔ＯＫＮ反应方向与刺激方向基本一致;其它方向上运动图形刺激时,家兔ＯＫＮ反应方向并没有随刺激方向的改变作相应变化,而基本集中在三个方向：水平鼻向、垂直向上及垂直向下附近,表明家兔ＯＫＮ的反应方向随不同刺激方向呈非线性的变化特性。     

复合运动条纹刺激下的视动震颤（OKN）眼动反应

研究视动震颤眼动系统在同时包含两个二维运动的复合运动条纹刺激下的反应特性,并探讨两种子条纹运动方向的夹角和运动速度的影响。实验结果发现,在一定参数范围内,复合运动条纹引起了双重交替ＯＫＮ反应,即ＫＯＮ交替地跟踪合成运动和分别运动;在跟踪分别运动中,又是交替地跟踪两种子条纹的运动。     

正常及异常双眼视觉的视动震颤（OKN）反应特性研究

为探讨不同双眼视觉状态下ＯＫＮ反应的特性,对正常人和不同类型的双眼视觉异常者的单眼鼻向及颞向ＯＫＮ反应进行了研究。实验发现：单眼视觉抑制者表现出鼻向与颞向ＯＫＮ反应不对称特性;两眼皆因视剥夺造成双眼视觉异常者主要以ＯＫＮ眼动增益降低为特点;双眼视觉正常者鼻、颞向ＯＫＮ反应是对称的。结果表明：单眼ＯＫＮ眼动反应的不对称特性及增益改变对探讨双眼视觉异常机制有重要意义,为视皮层双眼细胞异常导致单眼ＯＫＮ不对称的假设提供了支持性证据,并对弱视早期诊断及其分类有重要价值。     

用红外方法对蝇翅视动行为的探索

本文报告了利用红外装置对蝇翅视动行为实验研究的初步结果及其分析:1.在红外探测器探测到的信号中找到了一个能反映蝇翅拍动幅度的参数.2.双侧、单侧刺激域的宽度及刺激域的高度对视动反应发生几率在一定范围内正相关,当超过一阈值(即饱和阈值)后,即出现稳定的视动反应,它们的饱和阈值分别为60°,30°,40°刺激条纹的亮度生有类似情况.刺激条纹的运动速度在一定范围内对视动反应无影响.3.当刺激没有达到饱和时,蝇翅出现断续的典型的视动反应,即“0-1波动反应”.4.单侧条纹由前向后运动时,蝇翅出现典型反应,而条纹从后向前运动时,不出现典型的视动反应或反应很弱.双侧刺激时,条纹向前运动几乎不诱发反应;条纹向后运动诱发明显的蝇翅视动反应,且蝇翅平面的方向在拍动过程中发生变化.     

用红外方法对蝇翅视动行为的探索

本文报告了利用红外装置对蝇翅视动行为实验研究的初步结果及其分析:1.在红外探测器探测到的信号中找到了一个能反映蝇翅拍动幅度的参数.2.双侧、单侧刺激域的宽度及刺激域的高度对视动反应发生几率在一定范围内正相关,当超过一阈值(即饱和阈值)后,即出现稳定的视动反应,它们的饱和阈值分别为60°,30°,40°刺激条纹的亮度生有类似情况.刺激条纹的运动速度在一定范围内对视动反应无影响.3.当刺激没有达到饱和时,蝇翅出现断续的典型的视动反应,即“0-1波动反应”.4.单侧条纹由前向后运动时,蝇翅出现典型反应,而条纹从后向前运动时,不出现典型的视动反应或反应很弱.双侧刺激时,条纹向前运动几乎不诱发反应;条纹向后运动诱发明显的蝇翅视动反应,且蝇翅平面的方向在拍动过程中发生变化.     

外周炎性刺激条件下大鼠脊髓背角PPE mRNA及L-ENK样品和μ阿片受体样阳性结构的变化

以鹿角菜胶（ＣＡＲ）注射到大鼠一侧后爪的足底皮下作为伤害性刺激模型,分别于ＣＡＲ刺激后６、１２ｈ和１、３ｄ处死动物,对照组动物仅将盐水注入一侧后爪足底皮下,用原位杂交法和免疫组织化学法观察前原脑啡肽（ＰＰＥ）ｍＲＮＡ阳性神经元、亮氨酸脑啡肽（Ｌ－ＥＮＫ）和μ阿片受体（ＭＯＲ）样阳性结构在大鼠脊髓背角（ＳＤＨ）的分布和变化。对照组大鼠ＳＤＨ内可见到大量ＰＰＥｍＲＮＡ阳性神经元,这些阳性神经元主要分布于Ⅰ、Ⅱ层和Ⅴ、Ⅵ层,ＣＡＲ刺激后６ｈ,刺激侧ＳＤＨ中ＰＰＥｍＲＮＡ阳性神经元的数量明显增多,１２ｈ和１ｄ达到最高水平,３ｄ时略有下降,但仍高于正常水平。Ｌ－ＥＮＫ样阳性纤维和终末主要分布于正常大鼠ＳＤＨ的Ⅰ、Ⅱ层,ＣＡＲ刺激后１ｄ,Ｌ－ＥＮＫ样阳性结构在刺激侧ＳＤＨ中的密度略有升高,３ｄ后下降直至低于正常水平。ＭＯＲ阳性胞体和纤维主要分布于ＳＤＨ的Ⅱ层,ＣＡＲ刺激后１ｄ,刺激侧Ⅱ层中ＭＯＲ阳性结构明显增加,并持续到刺激后３ｄ。上述结果提示阿片类物质在伤害性信息调控中具有重要作用。     

Interocular motion combination for dichoptic moving stimuli

When gratings moving in different directions are presented separately to the two eyes, we typically perceive periods of the combination of motion in the two eyes as well as periods of one or the other monocular motions. To investigate whether such interocular motion combination is determined by the intersection-of-constraints (IOC) or vector average mechanism, we recorded both optokinetic nystagmus eye movements (OKN) and perception during dichoptic presentation of moving gratings and random-dot patterns with various differences of interocular motion direction. For moving gratings, OKN alternately tracks not only the direction of the two monocular motions but also the direction of their combined motion. The OKN in the combined motion direction is highly correlated with the perceived direction of combined motion; its velocity complies with the IOC rule rather than the vector average of the dichoptic motion stimuli. For moving random-dot patterns, both OKN and perceived motion alternate only between the directions of the two monocular motions. These results suggest that interocular motion combination in dichoptic gratings is determined by the IOC and depends on their form.     

The interstitial nucleus of Cajal of the cat. II. Effects of kainic acid lesion on vertical optokinetic nystagmus and after-nystagmus

The effects of bilateral lesions of the interstitial nucleus of Cajal (INC) by ka?nic acid on vertical optokinetic nystagmus (OKN) and after-nystagmus (OKAN) were studied in four cats: in three cats, in the acute stage from 1 to 60 days after the lesions; in the fourth cat, they were studied 3 years after the lesions were made. Histological control of lesions showed that the whole INC was bilaterally destroyed in two cats of the acute group and only the upper part of INC in the third cat. In the chronic cat, the density of cell bodies in both INC was lower than normal. In the acute group, the cats exhibited a spontaneous downward eye drift in light and in darkness. During an upward optokinetic stimulation, the effect of INC lesions was dramatic: upward slow phases and downward quick phases of OKN were abolished. Sixty days post lesions, small upward slow eye movements were again observed. During a downward optokinetic stimulation, the defect was much less; in particular, after a slight impairment of downward slow phases, during the first days post lesions, they recovered quickly. The secondary optokinetic after nystagmus (OKAN II) ensuing a downward OKN was cancelled and did not reappear 60 days post lesions. In the chronic stage, three years after the lesions, during an upward optokinetic stimulation, the cat showed upward slow phases with velocities close to normal. However, upward slow phases were curved: the velocity at the end of the slow phases was lower than at the beginning. After an upward OKN (the direction of slow phases gives the direction of the OKN and OKAN), the ensuing OKAN was present but abnormal.     

运图象刺动激的视动振颤(OKN)眼动反应的速度跟踪特性

本文用传统的转筒式运动条纹刺激及电视运动条纹图形刺激两种方法进行了OKN实验,对所引起的OKN反应进行了定量比较,结果证明两者的刺激效果是相似的;用电视运动图象刺激方法,分别在中心视场和周边视场进行刺激实验,阐明了OKN主要是由作用于视网膜中央区域的运动图象刺激所引起的;并对OKN的动态反应进行了实验分析,在正弦速度刺激下,OKN增益主要取决于刺激运动的加速度,而不是单纯取决于刺激运动的速度或频率,并在脉冲速度刺激的OKN实验中,用动态反应时间阐明了这一结论.     

不同运动图象同时刺激左右眼时的交替视动震颤(OKN)现象

采用了同时对左右眼分别以不同的运动图象刺激的实验方法,来测量及分析其OKN眼动反应,探索在OKN反映中两眼之间的输入关系以及眼动控制机制。实验结果发现在两眼的刺激图象不一致时,眼动反应为交替的OKN反应,即中枢神经系统根据各眼的刺激速度,交替地控制产生OKN眼动反应。本文还从闭环控制上讨论了视网膜上速度误差信号的作用。     

不同运动图象同时刺激左右眼时的交替视动震颤(OKN)现象

采用了同时对左右眼分别以不同的运动图象刺激的实验方法,来测量及分析其OKN眼动反应,探索在OKN反映中两眼之间的输入关系以及眼动控制机制。实验结果发现在两眼的刺激图象不一致时,眼动反应为交替的OKN反应,即中枢神经系统根据各眼的刺激速度,交替地控制产生OKN眼动反应。本文还从闭环控制上讨论了视网膜上速度误差信号的作用。     

Effect of the distance of optokinetic stimuli from the eyes on certain parameters of the optokinetic nystagmus.

The above effect was studied in 65 subjects with normal vision (mean age 20 years) in investigations in which the following factors were successively changed: distance of optokinetic stimuli from the eyes; this distance and angular velocity of stimuli; distance and frequency of stimuli or finally distance and accommodation level. The angular velocity of the pursuit nystagmus phase was found to be by far the highest and simultaneously the closest to the angular velocity of optokinetic stimuli when the latter are 1.5m from the eyes. With shorter distances, the velocity of the pursuit movements lags steadily behind that of stimulus velocity. This change is conditioned by changes in OKN amplitude since its frequency as a whole does not change. Even though the accommodation level significantly affects the velocity of the pursuit nystagmus phase, the dependence on the distance of optokinetic stimuli from the eyes persists even after atropinization. The interpretation of these findings must take into account sepcifically the demands on accommodation, convergence, and on visual attention which are increased with shorter distances.     

The interstitial nucleus of Cajal of the cat. I. Neurons activity related to vertical eye movements

Interstitial nucleus of Cajal (INC) neurons activity was studied during vertical optokinetic nystagmus (OKN) and after-nystagmus (OKAN) in awake cats lying on their right side. The activity of one hundred neurons was recorded in the left INC and analysed in relation with the vertical component of OKN and OKAN. The activity of 27 neurons was correlated either to eye position or to both eye velocity and eye position; 18 of these neurons were recorded in their on-direction and their off-direction. The analysis of the 18 neurons showed that the activity of 8 of them was correlated to eye position in the on-direction and in the off-direction and the correlation to eye position was higher than to eye velocity; these neurons are considered as position neurons. Seven other neurons had a higher correlation to eye position that to eye velocity in the on-direction and this relation reversed in the off-direction, these neurons are considered as position-velocity neurons. Thirty two burst-neurons were activated only during quick phases of OKN and OKAN and they were silent during slow phases and periods of fixation. Nine burst neurons had an upward on-direction and 23 neurons a downward on-direction. The eye velocity-average burst frequency (ABF) and quick phase duration-burst duration relationships had low correlations and suggested that INC burst neurons were excitatory premotor neurons. Statistical analysis showed that downward on-direction burst neurons had a higher ABF that upward on-direction burst neurons. Moreover, during OKN and OKAN, the velocity sensitivity of INC burst neurons was the same. The activity of the remaining neurons (41 neurons) was not quantitatively correlated to vertical and horizontal eye movements; they were classified as irregular tonic neurons. This study shows that INC neurons carry an eye position signal which was never reported before. This supports the results of INC lesion studies which showed that INC is involved in the vertical velocity to position integration. Moreover, there is an up versus down asymmetry in the frequency of INC burst neurons.