Spectral and temporal sensitivity of cone-mediated responses in mouse retinal ganglion cells.
J Neurosci
; 31(21): 7670-81, 2011 May 25.
Article
in En
| MEDLINE
| ID: mdl-21613480
ABSTRACT
The retina uses two photoreceptor types to encode the wide range of light intensities in the natural environment. Rods mediate vision in dim light, whereas cones mediate vision in bright light. Mouse photoreceptors include only 3% cones, and the majority of these coexpress two opsins (short- and middle-wavelength sensitive, S and M), with peak sensitivity to either ultraviolet (360 nm) or green light (508 nm). The M/S-opsin ratio varies across the retina but has not been characterized functionally, preventing quantitative study of cone-mediated vision. Furthermore, physiological and behavioral measurements suggested that mouse retina supports relatively slow temporal processing (peak sensitivity, â¼ 2-5 Hz) compared to primates; however, past studies used visible wavelengths that are inefficient at stimulating mouse S-opsin. Here, we measured the M/S-opsin expression ratio across the mouse retina, as reflected by ganglion cell responses in vitro, and probed cone-mediated ganglion cell temporal properties using ultraviolet light stimulation and linear systems analysis. From recordings in mice lacking rod function (Gnat1(-/-), Rho(-/-)), we estimate â¼ 70% M-opsin expression in far dorsal retina, dropping to <5% M-opsin expression throughout ventral retina. In mice lacking cone function (Gnat2(cpfl3)), light-adapted rod-mediated responses peaked at â¼ 5-7 Hz. In wild-type mice, cone-mediated responses peaked at â¼ 10 Hz, with substantial responsiveness up to â¼ 30 Hz. Therefore, despite the small percentage of cones, cone-mediated responses in mouse ganglion cells are fast and robust, similar to those in primates. These measurements enable quantitative analysis of cone-mediated responses at all levels of the visual system.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Photic Stimulation
/
Retinal Ganglion Cells
/
Retinal Cone Photoreceptor Cells
Type of study:
Diagnostic_studies
Limits:
Animals
Language:
En
Journal:
J Neurosci
Year:
2011
Document type:
Article
Affiliation country:
United States