We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
The sensitivity and spectral identity of the cones driving the b-wave of the rat electroretinogram.
- Authors
JAMES D. AKULA; ARKADY L. LYUBARSKY
- Abstract
In the retina of rat, cones make up ~0.85% of the photoreceptor population: 93% of these cones contain a midwave-sensitive pigment, the rest expresses a short-wave-sensitive pigment (Szel & Rohlich, 1992). We used normal adult Long Evans rats to determine the spectral sensitivity of the cone-driven electroretinogram (ERG) b-wave and its absolute sensitivity at λmax of the cone pigments. ERGs were recorded at the cornea of anesthetized animals under dark- and light-adapted conditions. Rod responses were suppressed by steady rod-saturating orange backgrounds and/or by a flashed white background. Cone-driven b-waves were evoked by white or narrowband full-field stimuli of varying intensity. The action spectrum for the cone b-wave indicates the presence of an absorbance peak at 510 nm; a second, twofold lower, peak was found at 360 nm (after correction for transmittance by the lens). Chromatic adaptation experiments strongly suggest that retinal responses to midwave and UV stimuli are mediated by a single cone type. On a background producing ~17,000 R* rod-1 s-1, which completely suppressed the saturated a-wave, the absolute sensitivity of the cone b-wave was 18 nV photon-1 μm2 at 510 nm and 4 nV photon-1 μm2 at 360 nm which is 2030 times higher than for the mouse. It is suggested that the relatively large number of on-cone bipolar cells in the retina of rat is responsible for the remarkable sensitivity of the cone b-wave.
- Subjects
RETINA; BIOLOGICAL pigments; CORNEA; LABORATORY rats
- Publication
Visual Neuroscience, 2003, Vol 20, Issue 2, p109
- ISSN
0952-5238
- Publication type
Article
- DOI
10.1017/s0952523803202029