Cognitive capacity was assessed in adult mice treated postnatally with proteasome inhibitors using the Y maze (A), object recognition test (B) and passive avoidance test (C). A, New arm preference in the Y maze was assessed during a short term memory test performed 2 minutes after a 10 minute training session (n = 16, 15 and 11 in control, MG132 and lactacystin treated animals, respectively). B, Discrimination index in short- and long-term (STM and LTM) memory training sessions in the object recognition test (n = 14, 11 and 6 in control, MG132 and lactacystin treated animals, respectively). C, Avoidance index during STM and LTM training sessions in the hot plate passive avoidance test (n = 8 mice per group). * indicates significant differences between the STM or LTM session compared with the training session; + indicates significant differences between groups in the same session. Black, gray and white bars represent mice treated with the vehicle alone, MG132 and lactacystin, respectively. * or +, p<0.05; ** or ++, p<0.01; ***, p<0.001.