Figure 3From: Variation in nocturnality and circadian activity rhythms between photoresponsive F344 and nonphotoresponsive Sprague Dawley rats Circadian parameters for F344 (F) and HSD (H) rats in LD, SD, and DD (Mean +/- SEM). (a) nocturnality index, (b) alpha, the duration of activity, (c) activity onset, with dashed lines indicating the time of lights off, (d) activity offset, with dashed lines indicating the time of lights on, (e) phase angle of entrainment, and (f) tau, the free-running rhythm in DD. Asterisks indicate significant differences between F344 and HSD rats.Back to article page