FIGURE 4.

Interaction between SERT deletion and cocaine self‐administration (short or long access) on the AMPA receptor subunits in the core nucleus accumbens. Protein levels of GluA1 (a) and GluA2 (b) are expressed as percentages of SERT^+/+‐naïve rats. Below the graphs, representative immunoblots are shown for GluA1 (108 kDa), GluA2 (108 kDa) and β‐actin (43 kDa) proteins. Histograms represent the mean ± SEM of the following number of rats: naïve (SERT^+/+ n = 7; SERT^−/− n = 7), short access (SERT^+/+ n = 6; SERT^−/− n = 6) and long access (SERT^+/+ n = 7; SERT^−/− n = 7). *P < .05 versus SERT^+/+‐naive; ^# P < .05 versus SERT^+/+‐short access; ^£ P < .01 versus SERT^−/−‐naive; °P < .05 versus SERT^−/−‐short access (Tukey's multiple comparisons test). N, naïve; S, Cocaine Short‐Access; L, Cocaine Long‐Access