Atypical Early Life Ultrasonic Vocalizations Disrupt the Pup-Dam Communication Dyad in the BTBR Model of Autism Spectrum Disorder.

Alterations in early-life communication are a defining feature of autism spectrum disorder (ASD). While these deficits are well conserved in mouse models, few studies have assessed how aberrations in neonatal vocalizations affect maternal behaviors and disrupt the pup-dam communication dyad. To better elucidate the consequences of altered communication in ASD models, we assessed ultrasonic vocalization (USV) production in pups and the corresponding retrieval behaviors in dams using C57 and BTBR (autistic-like) mice. We first used the pup's dam as the retriever and found that BTBR dams retrieved significantly fewer pups than C57 dams. We then used a novel C57 dam as the retriever and found that BTBR pups were retrieved significantly slower than C57 pups. Follow up analyses detected positive correlations between call duration and retrieval time and amplitude and retrieval time in BTBR pups. Similarly, we found that C57 mice that were retrieved the fastest had calls of a different amplitude than slowly retrieved mice. In the BTBR model, we found that faster retrieved mice produced shorter calls with a higher pitch than slowly retrieved mice, displaying call characteristics more similar to C57 pups. Lastly, we found that a more diverse call type repertoire was associated with a faster retrieval time. Overall, our study demonstrates that altered USV production significantly affects the pup-dam communication dyad. Furthermore, we identified the USV duration, amplitude, and a more diverse call type repertoire as being critical factors underlying maternal retrieval.