Figure 3.

SLC6A4 variant-specific anxiety response to an acute dose of a selective serotonin reuptake inhibitor, citalopram. Human intruder test (HIT) was used to assess anxiety levels in response to vehicle (V) and to a single dose of 2.5 mg/kg (D1) or 10 mg/kg (D2) citalopram, 25 min prior to the intruder phase. (a) Schematics of the home cage test quadrant in the HIT. High anxiety-related locations are shaded in red (high and rear) and low anxiety-related locations are shaded in blue (low and front). (b) Average distance. Repeated measures ANOVA, with within factor ‘treatment' and between factor ‘genotype'. Treatment × genotype interaction F₍₂₎=4.214, p=0.030; followed by LSD pairwise comparisons. D1: AC/C/G vs CT/T/C p=0.017; D2: AC/C/G vs CT/T/C p=0.012; AC/C/G: V vs D2 p=0.012, and CT/T/C: V vs D2 p=0.031. (c, d) Proportion of time spent at different locations (mean±SEM): Front, middle and back, for each group of homozygous AC/C/G (c) and CT/T/C (d). Two-way repeated measures ANOVA with ‘location' (front, middle, back) and ‘treatment' (V, D1, D2) as within factors and ‘genotype' as between factor (AC/C/G, CT/T/C). Genotype × treatment × location interaction F₍₄₎=6.530, p<0.001, followed by LSD post hoc comparisons. (c, middle panel) AC/C/G D1: front vs middle p=0.004; middle vs back p=0.027. (c, right panel) AC/C/G D2: front vs back p=0.001; middle vs back p=0.026. (d, right panel) CT/T/C D2: front vs back p=0.040. *p<0.05; **p<0.005.