Figure 6.
Object-in-place recognition memory assessed during abstinence from METH or saccharin self-administration. Schematic of the object-in-place recognition task with red objects indicating the novel targets (A). Exploration ratios during the test phase for naïve rats (B) or rats with a history of METH (C) or saccharin (D) self-administration. Bars represent exploration ratio averaged across the 3-min test phase with data points representing individual animal data. Exploration ratios were calculated as timenovel / (timenovel + timefamiliar). Dotted red line indicates chance performance (0.5). We found no significant sex difference, so data are presented collapsed across sex. * p < 0.01 vs. min 1, # p < 0.05 vs. min 2 within adult-onset, @ p < 0.05 age-of-onset effect collapsed across min.