Dopamine transporter blockade during adolescence increases adult dopamine function, impulsivity, and aggression

Area of Science:

• Neuroscience
• Developmental Biology
• Behavioral Science

Background:

• Sensitive developmental periods are critical for neural circuit formation but also confer vulnerability to disruptions.
• The dopamine system is crucial for adolescent behavior and exhibits heightened plasticity, making it susceptible to lasting alterations.
• Understanding dopamine-sensitive periods beyond sensory development is vital for comprehending neuropsychiatric disease etiology.

Purpose of the Study:

• To gain mechanistic insight into a specific dopamine-sensitive period during adolescence and its impact on adult behavior.
• To identify the neural correlates and behavioral consequences of dopamine transporter (DAT) blockade during this sensitive window.
• To investigate the role of specific dopaminergic pathways in mediating the observed behavioral changes.

Main Methods:

• Utilized a mouse model with dopamine transporter (DAT) blockade during specific postnatal days (P32-41).
• Assessed adult behaviors including aggression, impulsivity, cognition, working memory, and motivation.
• Employed in vitro and in vivo electrophysiology to measure dopaminergic neuron firing.
• Used optogenetics to selectively activate ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) dopamine neurons.

Main Results:

• Adolescent DAT blockade (P32-41) significantly increased adult aggression and impulsivity.
• This blockade led to increased firing of dopaminergic neurons, identified as a neural correlate.
• Impulsivity, but not cognition, working memory, or motivation, was affected in adulthood.
• Optogenetic activation of VTA dopamine neurons mimicked the increased impulsivity observed after DAT blockade.

Conclusions:

• Adolescence represents a critical dopamine-sensitive period where DAT blockade can induce long-lasting behavioral changes, specifically increased aggression and impulsivity.
• Altered dopaminergic neuron activity, particularly in the VTA, underlies these behavioral deficits.
• These findings provide crucial insights into the developmental origins of aggression and impulsivity, potentially informing diagnostic and therapeutic strategies for related neuropsychiatric disorders.