Subjects

A total of 210 male Sprague Dawley rats (275–300 g; Harlan Laboratories) were used in the study. Rats were housed in polyethylene cages and maintained on a 12 h light/dark schedule with ad libitum access to standard laboratory rat chow and water. Experiments were conducted during the light phase. All procedures were approved by the Institutional Animal Care and Use Committee of the University of Cincinnati. Separate cohorts of animals were used for each experiment as follows: (1) NPY dose response (48; 12 per group); (2) NPY consolidation (24; 12 per group); (3) Y₁ antagonist experiment (n = 48; 12 per group); (4) HPA (n = 24; 12 per group); (5) FST (n = 24; 12 per group); (6) delayed spatial win-shift (DSWS; n = 24; 12 per group); (7) electrophysiology (n = 13); and (8) immunohistochemistry (n = 5). For behavioral experiments, only data from IL hits was used for statistical analyses (see section for details).