TY - JOUR
T1 - Cone ERG Changes During Light Adaptation in Two All-Cone Mutant Mice
T2 - Implications for Rod-Cone Pathway Interactions
AU - Bush, Ronald A.
AU - Tanikawa, Atsuhiro
AU - Zeng, Yong
AU - Sieving, Paul A.
N1 - Copyright:
This record is sourced from MEDLINE/PubMed, a database of the U.S. National Library of Medicine
PY - 2019/8/1
Y1 - 2019/8/1
N2 - Purpose: The b-wave of the cone ERG increases in amplitude and speed during the first few minutes of adaptation to a rod-suppressing background light. Earlier studies implicate rod pathway input to the cone pathway in these changes. Methods: The timing and amplitude of the cone b-wave and isolated oscillatory potentials (OP) during the first 10 minutes of light adaptation in wild-type (WT) mice and two mutant lines without functional rods was examined: rhodopsin knockout (Rho-/-), lacking rod outer segments, and NRL knockout (Nrl-/-), in which rods are replaced by S-cones. Expression of the immediate-early gene c-fos, which is increased in the inner retina by light-induced activity, was evaluated by immunohistochemistry in dark- and light-adapted retinas. Results: WT b-wave and OP amplitudes increased, and implicit times decreased during light adaptation. Subtracting OP did not alter b-wave changes. Rho-/- b-wave and OP amplitudes did not increase during adaptation. B-wave timing and amplitude and the timing of the major OP at 1 minute of adaptation were equivalent to WT at 10 minutes. The light-adapted ERG b-wave in Nrl-/- mice, which originates in both the rod and cone pathways, changed in absolute amplitude and timing similar to WT. C-fos expression was present in the inner retinas of dark-adapted Rho-/- but not WT or Nrl-/- mice. Conclusions: Activity in the distal rod pathway produces changes in the cone ERG during light adaptation. Rods in Rho-/- mice constitutively activate this rod-cone pathway interaction. The rod pathway S-cones in Nrl-/- mice may maintain the WT interaction.
AB - Purpose: The b-wave of the cone ERG increases in amplitude and speed during the first few minutes of adaptation to a rod-suppressing background light. Earlier studies implicate rod pathway input to the cone pathway in these changes. Methods: The timing and amplitude of the cone b-wave and isolated oscillatory potentials (OP) during the first 10 minutes of light adaptation in wild-type (WT) mice and two mutant lines without functional rods was examined: rhodopsin knockout (Rho-/-), lacking rod outer segments, and NRL knockout (Nrl-/-), in which rods are replaced by S-cones. Expression of the immediate-early gene c-fos, which is increased in the inner retina by light-induced activity, was evaluated by immunohistochemistry in dark- and light-adapted retinas. Results: WT b-wave and OP amplitudes increased, and implicit times decreased during light adaptation. Subtracting OP did not alter b-wave changes. Rho-/- b-wave and OP amplitudes did not increase during adaptation. B-wave timing and amplitude and the timing of the major OP at 1 minute of adaptation were equivalent to WT at 10 minutes. The light-adapted ERG b-wave in Nrl-/- mice, which originates in both the rod and cone pathways, changed in absolute amplitude and timing similar to WT. C-fos expression was present in the inner retinas of dark-adapted Rho-/- but not WT or Nrl-/- mice. Conclusions: Activity in the distal rod pathway produces changes in the cone ERG during light adaptation. Rods in Rho-/- mice constitutively activate this rod-cone pathway interaction. The rod pathway S-cones in Nrl-/- mice may maintain the WT interaction.
UR - http://www.scopus.com/inward/record.url?scp=85071775446&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85071775446&partnerID=8YFLogxK
U2 - 10.1167/iovs.19-27242
DO - 10.1167/iovs.19-27242
M3 - Article
C2 - 31469895
AN - SCOPUS:85071775446
VL - 60
SP - 3680
EP - 3688
JO - Investigative Ophthalmology
JF - Investigative Ophthalmology
SN - 0146-0404
IS - 10
ER -