Circadian Rhythms are affected by mutations in NMDAR1. A) The rhythmic index of NMDAR1EP331 hypomorphs is normal compared to wild type. Flies homozygous for NMDAR1F654A and NMDAR1K558Q have severely reduced rhythmic index (p < 0.0001 and p < 0.01, respectively). B) The period length is unaffected in NMDAR1EP331 and NMDAR1K558Q animals. The period of NMDAR1F654A is calculated to be longer than wild type, but these flies are arrhythmic and this value is spurious, therefore interpretation of period for this allele is not meaningful. C) NMDAR1EP331 have normal activity levels, but NMDAR1F654A and NMDAR1K558Q are both less active (p < 0.0001). D-F) Actograms showing activity levels of wild type, NMDAR1EP331, NMDAR1F654A, and NMDAR1K558Q over six days in constant darkness. All circadian rhythmicity measures were conducted in constant darkness starting with newly eclosed animals that had been entrained for 3 days in a 12:12 light cycle. The gray and black bars on the x-axis represent the actual day and night cycle during the six days of imposed darkness.