Separate prefrontal-subcortical circuits mediate different components of risk-based decision making

Area of Science:

• Neuroscience
• Decision Science
• Behavioral Economics

Background:

• Individuals often face choices between smaller, guaranteed rewards and larger, uncertain ones.
• This decision-making process involves reconciling competing biases toward certainty or risk-taking.
• Understanding the neural underpinnings of these biases is crucial for explaining complex choices.

Purpose of the Study:

• To investigate the distinct neural pathways and circuits involved in decision biases toward certain versus risky rewards.
• To elucidate the roles of the medial prefrontal cortex (PFC), basolateral amygdala (BLA), and nucleus accumbens (NAc) in mediating these biases.
• To differentiate the functions of bottom-up and top-down communication between the PFC and BLA in reward-based decision-making.

Main Methods:

• Utilized disconnection techniques and neuroanatomical studies in rats to map and manipulate neural pathways.
• Disrupted communication within specific circuits, including BLA-NAc, BLA-PFC, and PFC-NAc.
• Exploited dissociable axonal pathways to selectively disrupt top-down and bottom-up information transfer between the BLA and PFC.

Main Results:

• Disrupting the BLA-NAc circuit biased choices toward larger, uncertain rewards.
• Disrupting BLA-PFC connections increased the preference for larger, riskier options.
• Selective disruption of top-down (PFC to BLA) communication, but not bottom-up, significantly increased risky choices, suggesting a role in regulating risk-seeking behavior.

Conclusions:

• Separate but interconnected neural circuits involving the PFC, BLA, and NAc underlie different decision biases.
• Top-down communication from the medial PFC to the BLA is critical for modulating the choice of riskier rewards.
• These findings offer novel insights into the neural mechanisms governing the dynamic competition between circuits that shape decision biases.