Reward loss and the basolateral amygdala: A function in reward comparisons

Area of Science:

• Neuroscience
• Behavioral Neuroscience

Background:

• Neural circuits for reward loss are not well understood.
• The central nucleus of the amygdala (CeA) is implicated in negative emotions from reward loss, but the basolateral nucleus (BLA) role is unclear.

Purpose of the Study:

• To investigate the function of the basolateral nucleus (BLA) in reward loss scenarios.
• To test hypotheses regarding BLA's role in negative emotion versus reward comparison.

Main Methods:

• Excitotoxic lesions of the BLA were performed in animals before behavioral training.
• Animals were trained on tasks including consummatory successive negative contrast (cSNC), autoshaping (AS), anticipatory negative contrast (ANC), and open field testing (OF).

Main Results:

• BLA lesions significantly reduced cell counts in the BLA.
• Lesions eliminated cSNC and ANC, and accelerated AS extinction, indicating impaired reward comparison.
• BLA lesions did not affect open field testing (OF), suggesting no role in negative emotion-based behaviors.

Conclusions:

• Results support the hypothesis that BLA neurons are critical for reward comparison mechanisms.
• A circuit including the thalamus, insular cortex, and BLA may underlie the comparison of current and expected rewards.