| First Author | Van der Zee EA | Year | 2008 |
| Journal | Curr Biol | Volume | 18 |
| Issue | 11 | Pages | 844-8 |
| PubMed ID | 18514517 | Mgi Jnum | J:137722 |
| Mgi Id | MGI:3801562 | Doi | 10.1016/j.cub.2008.04.077 |
| Citation | Van der Zee EA, et al. (2008) Circadian time-place learning in mice depends on Cry genes. Curr Biol 18(11):844-8 |
| abstractText | Endogenous biological clocks allow organisms to anticipate daily environmental cycles. The ability to achieve time-place associations is key to the survival and reproductive success of animals. The ability to link the location of a stimulus (usually food) with time of day has been coined time-place learning, but its circadian nature was only shown in honeybees and birds. So far, an unambiguous circadian time-place-learning paradigm for mammals is lacking. We studied whether expression of the clock gene Cryptochrome (Cry), crucial for circadian timing, is a prerequisite for time-place learning. Time-place learning in mice was achieved by developing a novel paradigm in which food reward at specific times of day was counterbalanced by the penalty of receiving a mild footshock. Mice lacking the core clock genes Cry1 and Cry2 (Cry double knockout mice; Cry1(-/-)Cry2(-/-)) learned to avoid unpleasant sensory experiences (mild footshock) and could locate a food reward in a spatial learning task (place preference). These mice failed, however, to learn time-place associations. This specific learning and memory deficit shows that a Cry-gene dependent circadian timing system underlies the utilization of time of day information. These results reveal a new functional role of the mammalian circadian timing system. |
