Orbitofrontal or accumbens dopamine depletion does not affect risk-based decision making in rats

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Decision Science

Background:

• Dopamine (DA) signals in specific brain regions are crucial for risk-based decision-making.
• The roles of DA in the orbitofrontal cortex (OFC) and nucleus accumbens shell (AcbS) remain largely unknown.

Purpose of the Study:

• To investigate the contribution of DA in the OFC and AcbS to risk-based decision-making.
• To examine the effects of DA depletions in these regions on choice behavior in rats.

Main Methods:

• Rats underwent 6-hydroxydopamine-induced DA depletions in the OFC and AcbS.
• A two-lever choice task assessed risky choice with varying reward probabilities.
• Systemic administration of amphetamine or cocaine was used.

Main Results:

• Systemic amphetamine or cocaine increased preference for the larger, riskier reward.
• Rats with OFC or AcbS DA depletions exhibited sensitivity to changing reward probabilities.
• These DA-depleted rats displayed normal probabilistic discounting, similar to controls.

Conclusions:

• DA input to the AcbS and OFC is not critical for the fundamental ability to assess reward magnitude and probability.
• The basal capacity for evaluating risks in decision-making does not depend on OFC or AcbS DA.
• These findings differentiate the roles of DA in various brain circuits for decision-making.