Figure 5.
5-HT2B receptor mRNA and protein expression in raphe nucleus. a, Total RNA were isolated from 5-HT2B+/+ or 5-HT2B−/− mice raphe nucleus. Putative contaminating genomic DNA was removed by digestion with RNase-free DNase. RT was omitted in samples indicated RT(−) as a control. On these samples, we used β-actin mRNA amplification, as positive control. We found 5-HT2B receptor mRNA only in WT mice raphe nucleus (first panel). b, BW723C86 (preferential 5-HT2B receptor agonist) injection (arrow) through microdialysis probe (10 nmol) in the raphe nucleus produced an increase in 5-HT extracellular concentration (open squares). Pretreatment with RS127445 (100 nm; selective 5-HT2B receptor antagonist) completely blocked BW723C86-induced 5-HT increase (filled circles), whereas RS127445 alone (open circles) had no effect on basal 5-HT concentration (filled squares). Data (means ± SEM; n = 5 per group) were analyzed using two-way ANOVA (repeated measures); each drug's effects were compared with saline. Effect of BW723C86 on 5-HT level, F(3,70) = 52.31; p < 0.0001. A Bonferroni posttest was also applied. ***p < 0.001.