The 5-HT content of whole blood collected from SERTΔTH mice (n = 7), SERTfl/fl littermate controls (n = 8), and SERT−/− mice (n = 8) was determined using HPLC. A) Box plot indicates the median with interquartile range and whiskers denote standard deviation. The number of biological replicates (n values) is indicated below the boxes. 5-HT content was not significantly different in SERTΔTH and SERTfl/fl (ns, not significantly different, P = 0.65 Student’s t-test). Note: The 5-HT content of blood from SERT−/− mice was below the threshold of detection (< 5 pg / μL). B) Same data as panel in A expressed as a percentage of mean value of SERTfl/fl mice (ns, not significantly different, P = 0.65 Student’s t-test).