感受野外视觉刺激显著性对猫初级视皮层神经元反应的影响

发布时间：2018-04-16 12:09

本文选题：视觉显著性 + 感受野　；参考：《天津医科大学》2010年硕士论文

【摘要】：研究目的：研究感受野外不同显著性视觉刺激对猫初级视皮层神经元反应影响。研究方法：利用细胞外记录技术,记录麻醉状态下成年猫初级视皮层神经元在感受野内或伴有感受野外2。外不同的刺激组合模式下的反应。对不同刺激模式下的记录结果绘制神经元反应的刺激后时间直方图(Post-stimulus time-histograms, PSTH),从中提取出发放率、反应潜时和变异度等指标,用不同刺激模式下的发放率除以仅有感受野内刺激时发放率计算标准化反应,运用SPSS13.0对上述指标进行统计学分析。结果：1.感受野确定与面积整合曲线：给予感受野位置面积不断增大的圆形光栅刺激,刺激直径由2°开始递增至30°,根据其发放率随面积增大达到的第一个峰值从而得出经典感受野(classical receptive field, CRF)的面积。细胞发放率在刺激超出CRF后下降,根据其有无发放率再次增加分为抑制型和去抑制型。面积整合对时间特性的影响表现为当刺激面积增大至超出感受野后潜时变短,变异度变小(p0.05)。 2.感受野外视觉刺激对比度对神经元反应的调制作用：给予感受野内100%对比度最优调制特征的刺激以及伴有感受野2。外不同对比度(100%、70%、50%、30%和10%)刺激。根据伴有对比度100%感受野外刺激的标准化反应是否大于1,分为易化或抑制反应：易化反应随感受野外对比度改变符合quadratic模型：y=1.160+1.911x-1.554x2(其中y为标准化反应,x为感受野外对比度),p=0.026；抑制性反应随感受野外对比度降低,其抑制作用减弱,表现为标准化反应数值的增加,其反应潜时不符合任何模型。 3、感受野外视觉刺激方向对神经元反应的调制作用：当感受野外刺激光栅方向与感受野内光栅方向垂直时,在抑制反应表现为抑制作用减弱,表现为55%细胞翻转为易化反应；易化反应表现为表现为易化作用减弱,与上述quadratic模型曲线对比度为5%标准化反应对应。 4、感受野外视觉刺激拓扑形状对神经元反应的调制作用：当感受野外环形和C型拓扑形状刺激,在抑制性反应表现为抑制性作用减弱,易化性反应表现为易化作用减弱,分别与模型曲线对比度15%和15%对应。 5、感受野内对比度改变情况下感受野外视觉刺激对神经元反应调制作用：给予感受野内不同对比度视觉刺激(70%、50%、30%、10%)刺激伴有感受野外相同对比度或100%对比度视觉刺激。易化性反应和抑制性反应表现为感受野外100%对比度视觉刺激对神经元的作用大于与感受野具有相同对比度的视觉刺激对神经元反应的作用,除易化性反应于感受野内刺激对比度在10%状况下。 6、间隙作用：感受野外伴随刺激与感受野内刺激之间有间隙存在时,感受野外刺激对神经元的影响为：发放率增加(p0.05)。结论：感受野外视觉刺激显著性对视皮层初级神经元发放率的调制作用,随其视觉显著性增大,对神经元的调制作用增大。视觉刺激显著性相对强度可以通过感受野外视觉刺激显著性对视皮层初级神经元发放率的调制作用进行定量。间隙效应是感受野外伴随刺激对神经元的调制的一个重要的影响因素。
[Abstract]:Objective : To study the effects of different visual stimuli on cortical neurons in the primary visual cortex of cats .

Methods : Using extracellular recording technique , the responses of primary visual cortex neurons of adult cat were recorded in the receptive field or in the external stimuli combined mode . The post - stimulus time - histogram ( PSTH ) was used to calculate the post - stimulus time - histogram ( PSTH ) .

Results : 1 . receptive field determination and area integration curve : the circular grating stimulation with increasing area of receptive field was given , the stimulation diameter increased from 2 掳 to 30 掳 , and the area of classical receptive field ( CRF ) was obtained according to its release rate .

2 . The effects of field visual stimulation contrast on the response of neurons were observed : the stimulation of 100 % contrast optimal modulation feature in the receptive field and the external contrast ( 100 % , 70 % , 50 % , 30 % and 10 % ) were stimulated .
The inhibitory response decreased with the observed field contrast , and its inhibitory effect decreased , manifested as the increase of standardized reaction value , which did not accord with any model .

3 . The modulation effect of the field visual stimulation direction on the response of neurons was observed : when the direction of the field stimulation grating and the direction of the grating in the receptive field were felt , the inhibition reaction was weakened , and 55 % of the cells were turned to the facilitation reaction ;
The manifestation of the facilitation reaction was weakened , and the contrast ratio of the model curve was 5 % .

4 . The modulation effect of the topological shape of field visual stimulation on the response of neurons was observed : when the ring shape and the C - shaped topological form were felt , the inhibitory effect was weakened and the susceptibility reaction was weakened , and the contrast of the model curves was 15 % and 15 % respectively .

5 . The effect of field visual stimulation on neuron response was observed under the condition of contrast change in the receptive field : the visual stimuli with different contrast visual stimuli ( 70 % , 50 % , 30 % , 10 % ) in the receptive field were stimulated with the same contrast or 100 % contrast visual stimuli in the field .

6 . Gap effect : The effect of field stimulation on neurons was observed when there was a gap between the stimulation of the field and the stimulation of the receptive field : the release rate was increased ( p < 0.05 ) .

Conclusion : The effect of field visual stimulation on the modulation of primary neurons in the visual cortex increased with the increase of visual significance . The relative intensity of visual stimulus could be quantified by sensing the effect of field visual stimuli on the modulation of primary neurons in the visual cortex .

【学位授予单位】：天津医科大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R77

【参考文献】