Fig. 4: Exaggerated aggression in IST mice is underlied by GnRHR signaling.

Schematic drawings depicting the detailed protocols followed in experiments (Exp) A and B. Please note that each individual Exp has used different cohorts of animals. Deso: deslorelin (GnRHR agonist, 300 ng/Kg); Kp-10: Kisspeptin-10 (0.52 μg/Kg); RI: resident-intruder; WO: Washout (neither behavior nor injection) (A). Deslorelin (Deso, GnRHR agonist, 300 ng/Kg, light purple bars) increased the total percentage of time spent on aggression (two-tailed Student’s t test t₍₁₃₎ = 2.98, p = 0.01) as well as the number of attacks (Wilcoxon test W = 82, p = 0.007), and reduced attack latency (t test t₍₁₃₎ = 3.39, p = 0.004), non-aggressive social investigations (t test t₍₁₃₎ = 3.24, p = 0.006) and home cage exploration (t test t₍₁₃₎ = 2.4, p = 0.03) in IST mice (B). Cetrorelix (Ctrx, GnRHR antagonist, 0.5 mg/Kg, dark purple bars) strongly reduced the total percentage of time spent on aggression (t test t₍₆₎ = 6.36, p = 0.0007), the number of attacks (Mann–Whitney U test U = 10, p = 0.02), and increased the latency to attack U test (U = 13, p = 0.05) and homecage exploration (t test t₍₁₄₎ = 0.79, p > 0.0001) in IST mice without affecting social investigation (C). Finally, deslorelin did not affect either aggressive social, or exploratory behaviors in group-housed (GH) mice (D). *p < 0.05, **<0.01 vs vehicle. Data are presented as mean + s.e.m.