Fig. 3

Tph2 deficiency in rats leads to severe deficits in socio-affective communication during the first two weeks of life, as evidenced by reduced call emission rates. (A) Overview of the assessment of isolation-induced ultrasonic vocalizations in Tph2^−/− (KO) and Tph2^+/− (HET) rat pups, as compared to Tph2^+/+ (WT) littermate controls. (B) Exemplary spectrograms of isolation-induced ultrasonic vocalizations emitted by WT, HET, and KO on P12, depending on nesting condition. (C) Average number of isolation-induced ultrasonic vocalizations emitted across P2 to P14. (D) Average total calling time across P2 to P14. Developmental trajectories of (C′) the number of isolation-induced ultrasonic vocalizations and (D′) total calling time across P2 to P14. SN = standard nesting (blue), CN = communal nesting (orange). P = postnatal day. Data are expressed as mean ± SEM. Effect of genotype: ***^(black) WT vs. KO p < .001; **^(black) WT vs. KO p < .01. ***^(gray) HET vs. KO p < .001; Effect of nesting: + p < .05. N(WT-SN) = 16, N(HET-SN) = 18, N(KO-SN) = 19, N(WT-CN) = 12, N(HET-CN) = 12, N(KO-CN) = 17