Acute activation of DRN5HT neurons is anxiolytic but does not increase locomotion or impact thermoregulation. (A) Experimental plan of anxiety-related behavioral tests including the open field test (OFT) and the elevated plus maze (EPM). (B) Example Ethovision trace of mouse injected with saline vs. clozapine-N-oxide (CNO) in open field test (B1) and elevated plus maze (B2). The central area of the open field test is represented by the white box (B1) and the open arms of the elevated plus maze are show with yellow dashed lines (B2). (C) Time spent in the center of the open field test (C1), distance traveled (C2) and average velocity (C3), in mice injected with saline and CNO (n = 11). Mean + SEM, *p < 0.05, paired t-test. (D) Time spent in the open arm of the elevated plus maze test (D1), number of open arm entries (D2), distance traveled (D3), and average velocity (D4), following saline and CNO injection (n = 11). Mean + SEM, paired t-test. (E) Body temperature (left) and locomotor activity (LMA; right) following saline and CNO injection at ZT3 (n = 5). Mean ± SEM, repeated-measures two-way ANOVA. (F) Body temperature (left) and locomotor activity (LMA; right) following saline and CNO (n = 5) at ZT12. Mean ± SEM, repeated-measures two-way ANOVA.