| First Author | Yoshimura T | Year | 1998 |
| Journal | Brain Res | Volume | 779 |
| Issue | 1-2 | Pages | 188-93 |
| PubMed ID | 9473668 | Mgi Jnum | J:45462 |
| Mgi Id | MGI:1195455 | Doi | 10.1016/s0006-8993(97)01122-0 |
| Citation | Yoshimura T, et al. (1998) Decline of circadian photosensitivity associated with retinal degeneration in CBA/J-rd/rd mice. Brain Res 779(1-2):188-93 |
| abstractText | Although it is well known that visual image formation is mediated by rods and cones, photoreceptors implicated in entrainment of circadian rhythms remain unknown. In our previous study, 12-week-old CBA/J-rd/rd mice were found to show decreased sensitivity in circadian photoreception. Because rd gene induces different age-related degeneration of cones and rods, we have examined age-related changes in the sensitivity to a light pulse for phase-shifting the locomotor activity rhythms in CBA/J-rd/rd mice. Since mice have middlewave-sensitive cones (M-cone, 510 nm) and shortwave-sensitive cones (S-cone, 360 nm), a 15-min monochromatic light pulse (501.6 or 359 nm; 10 microW cm(-2) s(-1)) was given at circadian time (CT) 16, 2 weeks after being transferred to constant darkness (DD) and the magnitude of phase shift was determined. The amount of phase shift by a green light pulse (501.6 nm) gradually declined from 8 to 16 weeks after birth and the similar tendency was also observed on a UV pulse (359 nm). The similar pattern of age-related decline in the number of cones and circadian photosensitivity in CBA/J-rd/rd mice suggest that cones are involved in the circadian photoreception in mice. |
