Administration of IL-2 in adults increases rearing behavior (in contrast to periadolesence).

Mean (± S.E.M.) activity scores (A. Number of rearing episodes within 3 sec; B. Number of rearing against wall episodes within 3 sec; C. Total number of rearing episodes; D. Total time spent rearing (sec)) following a single injection of saline or IL-2 (0.4 µg/mouse, s.c.) and those tested 30 days later with single injection of IL-2 (0.4 µg/mouse, s.c.) administered 30 days later, as described in the figure with “+30 days” designation. Mice were exposed to the test cage immediately following cytokine administration. *p<0.05.