Brivanlou I H, Warland D K, Meister M
Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Neuron. 1998 Mar;20(3):527-39. doi: 10.1016/s0896-6273(00)80992-7.
Nearby retinal ganglion cells often fire action potentials in near synchrony. We have investigated the circuit mechanisms that underlie these correlations by recording simultaneously from many ganglion cells in the salamander retina. During spontaneous activity in darkness, three types of correlations were distinguished: broad (firing synchrony within 40-100 ms), medium (10-50 ms), and narrow (<1 ms). When chemical synaptic transmission was blocked, the broad correlations disappeared, but the medium and narrow correlations persisted. Further analysis of the strength and time course of synchronous firing suggests that nearby ganglion cells share inputs from photoreceptors conveyed through interneurons via chemical synapses (broad correlations), share excitation from amacrine cells via electrical junctions (medium), and excite each other via electrical junctions (narrow). It appears that the firing patterns in the optic nerve are strongly shaped by electrical coupling in the inner retina.
附近的视网膜神经节细胞常常几乎同步地发放动作电位。我们通过对蝾螈视网膜中的多个神经节细胞进行同步记录，研究了这些相关性背后的神经回路机制。在黑暗中的自发活动期间，区分出了三种类型的相关性：宽泛的（40 - 100毫秒内的放电同步）、中等的（10 - 50毫秒）和狭窄的（<1毫秒）。当化学性突触传递被阻断时，宽泛的相关性消失了，但中等和狭窄的相关性依然存在。对同步放电的强度和时间进程的进一步分析表明，附近的神经节细胞通过化学突触共享来自经由中间神经元传递的光感受器的输入（宽泛的相关性），通过电突触共享来自无长突细胞的兴奋（中等的），并通过电突触相互兴奋（狭窄的）。视神经中的放电模式似乎受到视网膜内层电耦合的强烈影响。
