Abstract
A KCl-filled microelectrode was inserted into toad's inverted retina to record slow potentials to microillumination or to even illumination.
1. Responses obtained from an inverted retina was compared with those recorded from an opened eyebulb, and from this experiment it was suggested that the pigment epithelium contributes to the c-wave of ERG.
2. Responses were divided into two types; positive and negative. It was possible to obtain the positive type by giving a slight damage to the receptor surface. The negative type was obtainable more easily in light adaptation than dark adaptation.
3. Properties of focal responses to microillumination were examined. In experiments in which a mechanical cut or twin stimulus spots were used it was confirmed that the spread of potential over 1mm. from the illuminated focus was not due to stray light. The latency of the response obtained at the illuminated spot was found shorter than that of the response obtained from a point of the surrounding area, as evidenced by comparison of the two records or by Lissajous' figure.
4. Slow potentials of positive and negative types were recorded from different layers of the retina and compared with similar experiments by previous workers.
5. It was discussed on the origin of each component of ERG.
