Fig. 3. Spontaneous behavioral changes in Fads(Δ/+) mice fed a normal chow diet.
a Representative double-plotted actograms of wheel-running activity in WT (i) and Fads(Δ/+) mice (ii, iii). Arrowheads depict hyperactivity bouts (HABs). b Total daily wheel-running activity for six months. Arrowheads depict HABs, and thick lines indicate depressive-like episodes. Individuals (i)–(iii) are identical to those (i)–(iii) in panel a, respectively. m, male; f, female. c Frequency of HABs. Male Fads(Δ/+) mice exhibited HABs significantly more often than WT mice (*P < 0.05, r = 0.503 [large ES], U-test). d Immobility time in the tail suspension test during HAB or the euthymic state. The immobility time of Fads(Δ/+) mice was significantly shorter during HABs (*P < 0.05, d = 1.03 [large ES], t-test). Data for euthymic WT mice are shown as a reference. There is a significant difference in immobility time between euthymic Fads(Δ/+) mice and euthymic WT mice. e Frequency of depression-like episodes. Female Fads(Δ/+) mice exhibited depression-like episodes (DEs) significantly more often than WT mice (*P < 0.05, r = 0.516 [large ES]). We have observed four female individuals that exhibited both DE and HAB; one of them is the individual (iv) in panel (b). The four animals were among 47 females that were fed a normal chow diet and examined for wheel-running behavior for more than four months. f Comparison of delayed activity, an indicator of abnormal circadian rhythms, during and two weeks before and after a depression-like episode. Fads(Δ/+) mice showed significantly higher delayed activity during episodes (***P < 0.001, r = 0.91 and 0.80 [large ES], paired U-test).