Role of ?2?3 in Cellular Synchronization of the Suprachiasmatic Nucleus Under Constant Light Conditions

By the effort to identify candidate signaling molecules important for formation of robust circadian rhythms in suprachiasmatic nucleus (SCN), mammalian center, here we characterize role ?2? proteins, synaptic initially identified as an auxiliary subunit voltage dependent calcium channel, rhythm formation. In situ hybridization study demonstrated that type 3 gene (?2?3) was strongly expressed SCN. Mice without this isoform (Cacna2d3?/?) did not maintain proper locomotor activity under a constant light (LL) condition, whereas dark (DD) these mice showed similar period length and light-responsiveness compared wild mice. Reflecting behavioral phenotype, Cacna2d3?/? severely impaired Per1 expression SCN LL, but DD. Cultured slices from Per1-luc transgenic revealed reduced synchrony among neurons. These findings suggest ?2?3 is essential synchronized cellular oscillations thereby contributes enhancing sustainability behavior.