Mori S, Miller W H, Tomita T
Jpn J Physiol. 1976;26(2):203-17. doi: 10.2170/jjphysiol.26.203.
Using microelectrodes, the field potential change associated with SD (SDP) was recorded from frog retinas conditioned with Cl-free Ringer's. In such retinas, SDP was induced by light or chemical agents such as glutamate, aspartate and K+. The chemicals, when applied iontophoretically, produced a local graded response which eventually triggered SDP. A potential similar to the local response to chemicals was often discerned on the rising phase of SDPs produced by light or occurring spontaneously. The SDP was maximal across an innermost retinal layer 50 mum or less in thickness with the intraretinal polarity predominantly negative, indicating that the major sink of SDP is in the inner plexiform layer. The influence of SDP on the receptor potential was relatively small, but the other components completely disappeared at the beginning of SDP, recovering gradually thereafter. Concomitantly, a strong depolarization occurred in the ganglion cells. Stimulation of the optic nerve could induce SDP, but nerve impulse activity is not important for SDP because tetrodotoxin was unable to prevent SDP due to light or chemical agents.
使用微电极，从用无氯林格氏液处理过的青蛙视网膜记录与去极化（SDP）相关的场电位变化。在这样的视网膜中，SDP由光或化学试剂如谷氨酸、天冬氨酸和K⁺诱导产生。这些化学物质通过离子电泳施加时，会产生局部分级反应，最终引发SDP。在由光产生或自发出现的SDP的上升阶段，常常能识别出一种类似于对化学物质的局部反应的电位。SDP在厚度为50微米或更小的最内层视网膜层上最大，视网膜内极性主要为负，这表明SDP的主要汇在内部神经丛层。SDP对感受器电位的影响相对较小，但其他成分在SDP开始时完全消失，此后逐渐恢复。与此同时，神经节细胞中发生强烈的去极化。刺激视神经可诱导SDP，但神经冲动活动对SDP并不重要，因为河豚毒素无法阻止由光或化学试剂引起的SDP。
