Dorsal Raphe Serotonergic Neurons Control Intertemporal Choice under Trade-off

Area of Science:

• Neuroscience
• Behavioral Biology
• Decision Science

Background:

• Animals often face choices between immediate and delayed rewards, with delaying gratification being crucial for survival.
• Dorsal raphe (DR) serotonergic neurons are implicated in processing delayed rewards, but their causal role in choice behavior remains unclear.

Purpose of the Study:

• To investigate the causal role of DR serotonergic neurons in intertemporal choice behavior.
• To determine if modulating DR serotonergic neuron activity can influence impulsive choice in mice.

Main Methods:

• Mice performed a novel odor-guided intertemporal choice task involving differently delayed rewards.
• Transient augmentation or reduction of DR serotonergic neuron activity was performed at the decision point.
• Serotonergic projections to the nucleus accumbens (NAc) were also manipulated.

Main Results:

• Modulation of DR serotonergic neuron activity bidirectionally influenced impulsive choice.
• The effects were specific to choices with more difficult trade-offs.
• Similar effects were observed when manipulating serotonergic projections to the NAc.

Conclusions:

• DR serotonergic neurons play a critical role in suppressing impulsive choice by regulating decision trade-offs.
• These neurons appear to preemptively process reward delays at the decision point.