THE ROLE OF GAMMA-AMINOBUTYRIC ACID MEDIATED INHIBITION IN THE RESPONSE PROPERTIES OF CAT LATERAL GENICULATE-NUCLEUS NEURONS
THE ROLE OF GAMMA-AMINOBUTYRIC ACID MEDIATED INHIBITION IN THE RESPONSE PROPERTIES OF CAT LATERAL GENICULATE-NUCLEUS NEURONS
复制标题
DOI：
10.1113/jphysiol.1984.sp015514
复制
发表时间：
1984-01-01
影响因子：
5.5
通讯作者：
MORRONE, MC
中科院分区：
文献类型：
--
作者：
BERARDI, N;MORRONE, MC
本文研究了局部应用荷包牡丹碱对猫外侧膝状体A层细胞对正弦光栅和光斑刺激反应的影响。应用荷包牡丹碱使X和Y细胞的自发放电和视觉驱动放电均增加。在漂移正弦光栅刺激，X和Y细胞的平均放电保持不变，在正常条件下增加对比度。应用荷包牡丹碱引起的平均放电增加与对比，表明平均放电的恒定性是由GABA介导的抑制。在正常情况下，X和Y细胞对正弦光栅刺激的反应调制幅度随刺激对比度的增加而单调增加。在荷包牡丹碱应用期间，X细胞而非Y细胞的对比度-响应曲线的斜率增加，表明抑制X细胞（而非Y细胞）的调制的抑制是对比度依赖性的。乙酰胆碱的应用也增加了平均放电和调制的细胞反应的幅度，但这种增加并不依赖于刺激对比度。在正常情况下，X细胞而不是Y细胞表现出对低空间频率的响应衰减和对比度阈值增加。这种衰减在荷包牡丹碱应用期间消失。Y细胞反应曲线的形状不受荷包牡丹碱的影响。荷包牡丹碱对Y细胞反应的非线性成分和线性成分具有相同的作用。虽然荷包牡丹碱对X细胞和Y细胞对光栅刺激的反应有不同的影响，但它将X细胞和Y细胞的拮抗性周围降低到相似的程度（通过用闪光点绘制细胞感受野来揭示）。
The effect of local ionophoretic application of bicuculline on the response of cat lateral geniculate nucleus (laminae A) cells to stimulation by sinusoidal gratings and spots of light was studied. Application of bicuculline produced an increase both of spontaneous and visually driven discharge of both X and Y cells. On stimulation by drifting sinusoidal gratings, the average discharge of both X and Y cells remained constant with increasing contrast under normal conditions. Application of bicuculline caused the average discharge to increase with contrast, indicating that the constancy of the average discharge was maintained by GABA mediated inhibition. Under normal conditions, the amplitude of response modulation of both X and Y cells to sinusoidal grating stimulation increased monotonically with stimulus contrast. During bicuculline application, the slope of the contrast-response curve for X cells, but not for Y cells, increased, indicating that the inhibition which dampened the modulation of X cells (but not Y cells) was contrast dependent. Application of acetylcholine also increased the average discharge and the amplitude of modulation of the cell responses, but this increase did not depend on stimulus contrast. Under normal conditions, X but not Y cells showed an attenuation of response and an increase in contrast threshold to low spatial frequencies. This attenuation vanished during bicuculline application. The shape of Y-cell response curves was unaffected by bicuculline. Bicuculline had the same effect on the non-linear component of Y-cell response as on the linear component. Although bicuculline had a different effect on the response of X and Y cells to stimulation by gratings, it reduced the antagonistic surround of both X and Y cells to a similar extent (revealed by plotting the cell receptive fields with flashed spots of light).