Deficits in temporal processing in mice prenatally exposed to Valproic Acid

Area of Science:

• Neuroscience
• Cognitive Science
• Animal Models

Background:

• Interval timing, crucial for daily function, relies on cortico-striatal circuits and dopamine.
• Autism spectrum disorder (ASD) is linked to altered time estimation in humans.
• No prior studies have investigated interval timing in animal models of ASD.

Purpose of the Study:

• To evaluate interval timing in a mouse model of prenatal valproic acid (VPA) exposure, a model for ASD.
• To assess the impact of VPA on timing accuracy, precision, and scalar properties.
• To investigate the effect of early social enrichment on timing deficits in male VPA mice.

Main Methods:

• Peak-interval (PI) procedures with 15-s and 45-s intervals were used.
• Behavioral assessments evaluated timing responses in VPA-exposed and control mice.
• Striatal catecholamine levels were analyzed using High-Performance Liquid Chromatography with Electrochemical Detection (HPLC-ED).

Main Results:

• VPA-exposed mice (both sexes) exhibited reduced timing accuracy and precision compared to controls.
• Deviations from the scalar property of time perception were observed in VPA mice.
• Social enrichment ameliorated timing deficits in male VPA mice.
• VPA exposure altered striatal dopaminergic content, but not serotonergic content, in both sexes.

Conclusions:

• Prenatal VPA exposure in mice induces interval timing deficits, mirroring human ASD findings.
• These deficits are associated with altered striatal dopamine levels.
• Early social enrichment offers a potential intervention for timing impairments in male VPA mice.
• This VPA mouse model provides a valuable platform for further autism research and pharmacological studies.