biostudies-literatureSmyllie NJRCUK | Biotechnology and Biological Sciences Research CouncilRCUK | Medical Research CouncilBiotechnology and Biological Sciences Research Councile2113845119https://www.ebi.ac.uk/biostudies/studies/S-EPMC8795536biostudies-literatureUnknown119(4)The ∼20,000 cells of the suprachiasmatic nucleus (SCN), the master circadian clock of the mammalian brain, coordinate subordinate cellular clocks across the organism, driving adaptive daily rhythms of physiology and behavior. The canonical model for SCN timekeeping pivots around transcriptional/translational feedback loops (TTFL) whereby PERIOD (PER) and CRYPTOCHROME (CRY) clock proteins associate and translocate to the nucleus to inhibit their own expression. The fundamental individual and interactive behaviors of PER and CRY in the SCN cellular environment and the mechanisms that regulate them are poorly understood. We therefore used confocal imaging to explore the behavior of endogenous PER2 in the SCN of PER2::Venus reporter mice, transduced with viral vectors expressing various forms Proceedings of the National Academy of Sciences of the United States of AmericaCryptochrome proteins regulate the circadian intracellular behavior and localization of PER2 in mouse suprachiasmatic nucleus neurons.PMC8795536MC_U105170643BB/P017347/1Chin JWPartch CLLoudon ASISmyllie NJBagnall JChesham JEPolidarova LKoch AANiranjan DHastings MHfalseCryptochrome proteins regulate the circadian intracellular behavior and localization of PER2 in mouse suprachiasmatic nucleus neurons.The ∼20,000 cells of the suprachiasmatic nucleus (SCN), the master circadian clock of the mammalian brain, coordinate subordinate cellular clocks across the organism, driving adaptive daily rhythms of physiology and behavior. The canonical model for SCN timekeeping pivots around transcriptional/translational feedback loops (TTFL) whereby PERIOD (PER) and CRYPTOCHROME (CRY) clock proteins associate and translocate to the nucleus to inhibit their own expression. The fundamental individual and interactive behaviors of PER and CRY in the SCN cellular environment and the mechanisms that regulate them are poorly understood. We therefore used confocal imaging to explore the behavior of endogenous PER2 in the SCN of PER2::Venus reporter mice, transduced with viral vectors expressing various forms 2022-01-01T00:00:00Z2022 Jan2025-04-04T21:33:45.749Z2025-04-04T21:33:45.749ZS-EPMC87955363504603310.1073/pnas.2113845119