Nucleus Accumbens Fast-Spiking Interneurons Constrain Impulsive Action

Area of Science:

• Neuroscience
• Behavioral Neuroscience

Background:

• The nucleus accumbens (NAc) is a key brain region involved in controlling impulsivity.
• Fast-spiking interneurons (FSIs) within the NAc are a major source of inhibitory signaling.
• Previous research suggests gamma-aminobutyric acid (GABA) signaling in the NAc is linked to impulsive behavior.

Purpose of the Study:

• To investigate the role of NAc FSIs in regulating impulsive behavior.
• To determine how FSI activity influences sustained attention and premature responses.

Main Methods:

• Utilized transgenic mice for FSI identification in the NAc.
• Employed the 5-choice serial reaction time task to assess impulsivity and attention.
• Used fiber photometry, chemogenetics, and optogenetics to monitor and manipulate FSI activity.

Main Results:

• NAc FSI activity was sustained during correct responses but declined during premature responses.
• Inhibition of NAc FSIs significantly increased premature responses.
• Locomotor activity and response latencies remained unchanged after FSI inhibition.

Conclusions:

• NAc FSIs play a crucial role in constraining impulsive actions.
• This control is likely mediated by GABAergic inhibition of medium spiny projection neurons.
• Findings offer insights into impulsivity disorders and potential circuit-based therapies.