Effects of chronic lithium treatment on nesting building. (a) Bouts of exploration and shredding of the nesting material. Main effects of genotype (F(1, 37) = 233.31, p < 0.0001), drug (F(1, 37) = 9.80, p < 0.01) and genotype × drug interaction (F(1, 37) = 5.39, p < 0.05) on bouts of shredding were observed. (b) Time spent exploring and shredding the nesting material over 5 min of observation in a clean cage. Main effects of genotype (F(1, 37) = 18.06, p < 0.0001) and drug (F(1, 37) = 4.39, p < 0.05) on time spent exploring, and a main effect of genotype (F(1, 37) = 101.27, p < 0.0001) on time spent shredding, were observed. (c) Nest quality score (0–4 scale) at 30 min, 60 min, 90 min, 3 h and 24 h after placement into a clean cage. Main effects of genotype (F(1, 212) = 595.26, p < 0.0001), drug (F(1, 212) = 9.87, p < 0.0001), time (F(4, 212) = 74.68, p < 0.0001), genotype × drug interaction (F(1, 212) = 24.82, p < 0.0001) and genotype × time interaction (F(4, 212) = 33.99, p < 0.0001) were observed. (d) Percentage of nestlet shredded at 30 min, 60 min, 90 min, 3 h and 24 h after placement into a clean cage. Main effects of genotype (F(1, 212) = 579.50, p < 0.0001), drug (F(1, 212) = 21.25, p < 0.0001), time (F(4, 212) = 100.05, p < 0.0001), genotype × drug interaction (F(1, 212) = 38.89, p < 0.0001), genotype × time interaction (F(4, 212) = 67.39, p < 0.0001), sex × drug interaction (F(1, 212) = 5.39, p < 0.05) and drug × time interaction (F(4, 212) = 5.69, p < 0.0001) were observed. (e) Height of nests at 24 h after placement into a clean cage. A main effect of genotype (F(1, 40) = 238.88, p < 0.0001) was observed. Myk/+ mice on standard diet (n = 15); Myk/+ mice on lithium diet (n = 11); +/+ mice on standard diet (n = 8); +/+ mice on lithium diet (n = 10). *p < 0.05; **p < 0.01; ****p < 0.0001 Myk/+ mice on standard diet versus +/+ mice on standard diet. #
p < 0.05; ###
p < 0.001 +/+ mice on lithium diet versus +/+ mice on standard diet.