Urine Scent Marking (USM): A Novel Test for Depressive-Like Behavior and a Predictor of Stress Resiliency in Mice
Figure 1
Male mice show a high preference for scent marking proestrous female urine.
a) A binary image of urine scent marks deposited by a male mouse during a 10 min period is overlaid with a diagram showing analyzed areas and quadrant locations. Marking preferences are calculated by dividing the area of male urine marks within a specified region by the total area of marks deposited in the arena. b) Males were exposed to the urine scent marking task for 5, 10, or 30 min and showed a significant preference for marking the quadrant with female urine after 10-min trial. Insert) The area of urine scent marks in the total arena increased significantly across trial length. c, d, f) In a time course analysis of the duration spent in each of the four quadrants for the c) 5, d) 10, or f) 30 min trial periods, male mice show a preference for the quadrant containing female urine during the first min only. Densitometry plots that indicate location preferences during different trial lengths are shown to the right of each line graph. e) Legend for the line graphs and densitometry plots indicating quadrant location. Bars represent mean+SE (n = 10–12 per group), *p<0.05, ***p<0.001.