Fig. 1.

Anxiolytic effect of mating in males. Male Wistar rats were tested on the elevated plus maze (a, c, and d) and in the black–white box (b) 30 min (a and b), 120 min (c), and 240 min (d) after termination of a 30-min mating period. Male rats were either single-housed (yellow) or exposed to a nonreceptive (nonmated group; orange) or an estrogen/progesterone-primed (mated group; red) female rat in their home cage in the dark phase. Reduced anxiety levels were found in mated males at all three time points as indicated by increased exploration of the open arms of the plus maze (a, c, and d) and of the lit compartment of the black–white box (b), respectively. The locomotor activity (number of entries into the closed arms of the plus maze) (a, c, and d) was not altered by mating. Data represent means + SEM. Group size was as follows: single-housed: a, n = 8; b, n = 8; c, n = 12; d, n = 9; nonmated: a, n = 13; b, n = 9; c, n = 11; d, n = 10; mated: a, n = 7; b, n = 11; c, n = 10; d, n = 11. ★★, P < 0.001; ★, P < 0.05 versus single-housed and nonmated males; #, P < 0.05 versus single-housed males after ANOVA.