Hypersociability in the Angelman syndrome mouse model

Area of Science:

• Neuroscience
• Genetics
• Developmental Biology

Background:

• Angelman syndrome is a neurodevelopmental disorder caused by maternal UBE3A gene loss.
• Increased UBE3A gene dosage is linked to decreased sociability, resembling autism spectrum disorder features.
• Angelman syndrome patients exhibit unique social behaviors, including increased smiling and eye contact.

Purpose of the Study:

• To investigate the hypothesis that neuronal UBE3A loss, modeling Angelman syndrome, leads to hypersocial behavior.
• To examine the role of UBE3A in regulating social motivation and behavior.

Main Methods:

• Utilized a mouse model with maternally-inherited Ube3a gene deletion (Ube3a^mKO).
• Assessed social behavior using the three-chamber social approach task.
• Measured ultrasonic vocalizations and physical contact during social interactions.
• Investigated the effect of single housing on social behavior in wild-type and Ube3a^mKO mice.

Main Results:

• Ube3a^mKO mice demonstrated a prolonged preference for and interaction with social stimuli.
• Interactions with novel objects were reduced in Ube3a^mKO mice.
• Both male and female Ube3a^mKO mice exhibited increased ultrasonic vocalizations and physical contact.
• Single housing, a form of social deprivation, increased social behaviors in wild-type mice, partially occluding the effect in Ube3a^mKO mice.

Conclusions:

• Neuronal UBE3A loss in Angelman syndrome models is associated with increased social motivation.
• Sociability is regulated by both endogenous UBE3A levels and social experience.
• Findings suggest that some social deficits in Angelman syndrome may stem from amplified social drive.