Nkx2.1-CBPKO mice exhibit impaired learning and other behavioral alterations. a Time spent in the center and periphery of the arena in an open field task. b Total distance run in the open field task. c Nkx2.1-CBPKO mice spent less time resting in the open field (F(1,192) = 14.01, p < 0.001). d Time occupancy of the closed and open arms in the EPM (closed arms, F(1,29) = 7.06, p = 0.01; open arms, F(1,29) = 5.82, p = 0.02). e Number of arms entries in the EPM. f Freezing in response to a foot shock. g Freezing to the context 24 h after receiving the foot shock. h Preference index for interacting with a mouse-containing cylinder or empty cylinder in the three-chamber social interaction task. i Total distance traveled in the social interaction task (F(1,29) = 6.68, p = 0.01). j Working memory in a Y-maze measured as the percentage of turn alternations. k Percentage of time spent as immobile in the forced swimming test. l Number of marbles buried in the marble-burying test. m Latency to fall from the rotarod after various days of training. n Swimming speed during training in the radial arm maze. o Number of reference memory errors in the radial water maze (hidden phase, F(1,235) = 3.76, p = 0.05). *P < 0.05; ***P < 0.001