An Analysis of the D.C. Component of the Local Electroretinogram in the Intact Eye of the Cat

摘要

The local electroretinogram (LERG) was recorded with microelectrodes from the intact eye in response to focused spots and annuli delivered by a dual-beam ophthalmoscope. The d.c. component was readily isolated from the b-wave on the basis of a lower threshold, smaller summation area, and greater resistance to light adaptation, thereby supporting a hypothesis that separates these components. At high flash intensities the d.c. component increased in duration as its decay was delayed; a slowing in decay rate also occurred and an earlier off-response was revealed. These effects were influenced by flash duration and the level of light adaptation. The late receptor potential was also recorded from the area centralis after clamping the retinal circulation at the optic disk. At moderate levels of light adaptation it was isolated from the c-wave and exhibited a rapid decay-phase. The behavior of the late RP in response to increases in flash intensity and duration paralled the behavior of the d.c. component. (Author)