December 2002
Volume 43, Issue 13
ARVO Annual Meeting Abstract  |   December 2002
Stimulating Dark Adapted Opsins In Light Adapted Cones
Author Affiliations & Notes
  • BA Ekesten
    Dept of Ophthalmology University of Minnesota Minneapolis MN
  • P Gouras
    Dept of Ophthalmology Columbia University New York NY
  • Footnotes
    Commercial Relationships   B.A. Ekesten, None; P. Gouras, None. Grant Identification: Swedish Medical Council K 2000-73F-13366-01A
Investigative Ophthalmology & Visual Science December 2002, Vol.43, 3752. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      BA Ekesten, P Gouras; Stimulating Dark Adapted Opsins In Light Adapted Cones . Invest. Ophthalmol. Vis. Sci. 2002;43(13):3752.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Abstract: : Purpose: The common house mouse has two cone opsins, one with maximal absorbtion in the ultraviolet (UV) and one in the green part of the spectrum. Some cones co-express both opsins. UV stimuli are supressed by long wavelength adapting lights not absorbed by UV cone opsin. We have studied whether this suppression occurs in the cones or is due to postsynaptic interactions. Methods: The retina from normal C57B mice in a superfused eyecup preparation was examined. ERGs from these retinas were obtained in response to UV and green flashes. A 750 cd/m2 yellow background light was used to light adapt the retina. Responses were amplified and averaged by a computerized data acquisition system (PowerLab, AD Instruments, CA). Posynaptic transmission was blocked adding 2.5 mM kynurenic acid (KYN) and 1.5 mM aminophosphonobutyric acid (APB) to the superfusion fluid. Results: ERG responses to UV and green flashes could be obtained from the eyecups in the chamber for up to 10 hours. The steady yellow background eliminated responses to green stimuli and greatly reduced UV cone responses for at least 8-10 minutes. UV responses recovered in the yellow light within 10 minutes. KYN and APB blocked postsynaptic transmission resulting in a negative photoreceptor response. The addition of KYN and APB did not prevent the suppression or the recovery of the UV responses in presence of the yellow background but the responses to green flashes were completely eliminated. Conclusion: Postsynaptic interaction through second order retinal neurons is not involved in the supression of the UV response by yellow background light. The interaction between the UV and green mechanisms must occur within the same cone implying that cone desensitization occurs before transducin activation.

Keywords: 396 electroretinography: non-clinical • 555 retina: distal(photoreceptors, horizontal cells, bipolar cells) • 384 dark/light adaptation 

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.