Altered postnatal developmental patterns of ultrasonic vocalizations in Dock4 knockout mice

Area of Science:

• Neuroscience
• Animal Behavior
• Genetics

Background:

• Ultrasonic vocalizations (USVs) are crucial for rodent communication.
• USV analysis is a valuable tool for studying neurodevelopmental disorders like autism spectrum disorder (ASD).
• Dock4 gene mutations are linked to ASD, but their impact on vocal communication is not fully understood.

Purpose of the Study:

• To characterize the developmental trajectory of USVs in Dock4 knockout (KO) mice, a model for ASD.
• To compare the USV repertoire of Dock4 KO mice with their wild-type (WT) littermates during early postnatal development.
• To identify specific alterations in USV characteristics associated with Dock4 deficiency.

Main Methods:

• Comprehensive classification of USVs into 12 types.
• Recording and analysis of USVs emitted by Dock4 KO and WT pups during social isolation.
• Qualitative and quantitative assessment of USV repertoire characteristics, including note structure, pitch, and volume.

Main Results:

• Wild-type pups exhibited a developmental shift in USVs from complex, multi-note calls to simpler, single-note calls.
• Dock4 KO pups showed significantly different USV patterns compared to WT pups.
• Specifically, Dock4 KO pups emitted more multi-note calls with higher pitch and larger volume in later developmental stages.

Conclusions:

• This study reveals a distinct developmental pattern of USVs in normal mice.
• Dock4 deficiency leads to significant alterations in USV repertoire during early development.
• These findings highlight USV analysis as a potential biomarker for studying ASD-related communication deficits in mouse models.