Taylor W R
Neuroanatomische Abteilung, Max-Planck-Institut für Hirnforschung, Frankfurt, Germany.
Vis Neurosci. 1999 Mar-Apr;16(2):285-90. doi: 10.1017/s0952523899162096.
Patch-clamp recordings were made from ganglion cells in an in vitro dark-adapted rabbit retina preparation. Cells were stimulated by images generated on a computer monitor and focussed onto the photoreceptors. Excitatory inward currents were recorded in response to spot stimuli centered on the somas of the recorded cells. Center illumination of on-brisk-transient cells produced large transient excitatory postsynaptic currents (EPSCs) which were invariably followed by a small steady-state inward component. Illumination of a centered annulus failed to elicit the transient EPSC. Simultaneous illumination of the annulus and the center spot blocked the large transient EPSC, consistent with activation of an inhibitory surround. Application of tetrodotoxin (TTX), which blocks sodium-dependent action potentials, also blocked the surround inhibition in ON-brisk transient cells as well as some other classes of ganglion cells. It is concluded that, in some ganglion cell classes, the surround is generated largely through the activity of spiking neurons, and it is suggested that the amacrine cells in the inner plexiform layer are involved.
在体外暗适应的兔视网膜标本中，对神经节细胞进行膜片钳记录。细胞由计算机显示器上生成并聚焦于光感受器的图像刺激。记录到对以记录细胞胞体为中心的点状刺激产生的兴奋性内向电流。对“开 - 快瞬态”细胞的中心照明产生大的瞬态兴奋性突触后电流（EPSC），随后总是跟着一个小的稳态内向成分。对中心环形区域的照明未能引发瞬态EPSC。环形区域和中心光点同时照明会阻断大的瞬态EPSC，这与抑制性周边的激活一致。应用河豚毒素（TTX），它阻断钠依赖性动作电位，也阻断了“开 - 快瞬态”细胞以及其他一些类型神经节细胞中的周边抑制。得出的结论是，在某些类型的神经节细胞中，周边主要通过发放动作电位的神经元的活动产生，并且提示内层神经网中的无长突细胞参与其中。
