Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, United States.
Cullen Eye Institute, Baylor College of Medicine, Houston, TX 77030, United States.
Vision Res. 2023 Apr;205:108186. doi: 10.1016/j.visres.2023.108186. Epub 2023 Feb 8.
By using multi-electrode array (MEA) recording technique in conjunction with white-noise checkerboard stimuli and reverse correlation methods, we studied modulatory actions of glycinergic narrow-field amacrine cells (NFACs) on spatiotemporal profiles of five functional groups of ganglion cells (GCs) in dark-adapted mouse retinas. We found that application of 2 µM strychnine significantly altered light-evoked spike rates of three groups of GCs. It also decreased receptive field center radii of all five groups of GC by a mean value of 11%, and shifted the GC receptive field (RF) centers of all GCs and the mean shift distances for the sustained GCs are significantly longer than the transient GCs. On the other hand, strychnine did not affect temporal profiles of the GC center responses, as it did not alter the time-to-peak or the biphasic index of the spike triggered average (STA) functions of GC RF centers. Strychnine also exerts limited actions on RF surrounds of most GCs, except that it moderately weakens the antagonistic surround of sustained OFF GCs and strengthens the antagonistic surround of the ON/OFF GCs, possibly through serial connections between NFACs and GABAergic wide-field amacrine cells (WFACs). Using the Sum of Separable Subfilter (SoSS) model and singular value decomposition method, we decomposed GCs' STAs into five space-time separable subfilters, studied the observation rates of each subfilter in the five functional groups of GCs and determined NFAC-dependent and -independent synaptic circuitries that mediate center and surround responses of various groups of mouse retina retinal ganglion cells.
利用多电极阵列（MEA）记录技术，结合白噪声棋盘刺激和反向相关方法，我们研究了甘氨酸能窄场无长突细胞（NFAC）对暗适应小鼠视网膜 5 种功能群神经节细胞（GC）时空分布的调制作用。我们发现，应用 2μM 士的宁显著改变了 3 种 GC 光诱发的放电率。它还使所有 5 种 GC 的感受野（RF）中心半径平均减小 11%，并使所有 GC 的 RF 中心以及持续 GC 的平均移位距离显著长于瞬态 GC。另一方面，士的宁不影响 GC 中心反应的时间分布，因为它不改变 GC RF 中心的峰潜伏期或双相指数的触发平均（STA）函数。士的宁对大多数 GC 的 RF 周围区也只产生有限的作用，除了它适度地减弱持续 OFF GC 的拮抗性周围区和增强 ON/OFF GC 的拮抗性周围区，这可能是通过 NFAC 和 GABA 能宽场无长突细胞（WFAC）之间的串联连接。利用可分离子滤波器总和（SoSS）模型和奇异值分解方法，我们将 GC 的 STA 分解为 5 个时空可分离的子滤波器，研究了各子滤波器在 5 种功能群 GC 中的观察率，并确定了介导各种鼠视网膜神经节细胞中心和周围反应的 NFAC 依赖和非依赖的突触回路。
