Fig. 6

Effects of the selective 5-HT_2A receptor antagonist EMD 281014 on d-fenfluramine-induced c-fos expression in different regions at 5 coronal sections in the PFC of mice. Compared to the Vehicle + Vehicle control group, administration of d-fenfluramine (i.e. Vehicle + d-fenfluramine group) significantly induced c-fos expressions in the: (1) FrA at the level of − 2.68 mm relative to bregma (a); (2) M1 and AI at the level of − 2.34, and − 2.1 mm relative to bregma (c–f); (3) S1 and M1 at the level of − 1.98 mm relative to bregma (g); (4) S1 at the level of − 1.7 mm relative to bregma (i). Compared to the Vehicle + Vehicle group, EMD 281014 by itself (i.e. EMD 281014 + Vehicle group) did not cause any changes in c-fos expression in the PFC, whereas inclusion of d-fenfluramine (i.e. EMD 281014 + d-fenfluramine treatment group) significantly increased c-fos expression in the: (1) FrA and PrL at the level of − 2.68 mm relative to bregma (a); (2) M1 and AI at the level of − 2.34 mm relative to bregma (c, d); (3) M2 and AI at the level of − 2.1 mm relative to bregma (e, f); (4) S1, M1 and AI at the level of − 1.98 mm relative to bregma (g, h); (5) S1 at the level of − 1.7 mm relative to bregma (i). Compared to the EMD 281014 + Vehicle treatment group, inclusion of d-fenfluramine (i.e. EMD 281014 + d-fenfluramine treatment group) significantly increased c-fos expression in the: (1) PrL at the level of − 2.68 mm relative to bregma (a); (2) M1 and AI at the level of − 2.34 mm relative to bregma (c, d); (3) M2 at the level of − 2.1 mm relative to bregma (e); (4) S1 at the level of − 1.98 mm relative to bregma (g). However, EMD 281014 did not prevent d-fenfluramine -induced c-fos expressions in the areas of the PFC (i.e., EMD 281014 + d-fenfluramine treatment group vs. Vehicle + d-fenfluramine treatment group, (a–j). In addition, pre-treatment with EMD 281014 significantly increased d-fenfluramine-induced c-fos expression in the PrL at the level of − 2.68 mm relative to bregma (a). *p < 0.05, **p < 0.01, ***p < 0.001 vs. Vehicle + Vehicle pretreated control-mice; ^#p < 0.05 vs. Vehicle + d-fenfluramine treatment group; ^$p < 0.05, ^$$p < 0.01, ^$$$p < 0.001 vs. EMD 281014 + Vehicle group; one-way ANOVA followed by Tukey's test. Data are presented as means ± SEM