Prediction Error Determines Whether NMDA Receptors in the Basolateral Amygdala Complex Are Involved in Pavlovian Fear...

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Memory Research

Background:

• NMDA receptors (NMDAR) in the basolateral amygdala complex (BLA) are widely accepted as necessary for fear memory formation.
• This is based on studies showing NMDAR blockade in the BLA disrupts fear conditioning to unexpected aversive stimuli.

Purpose of the Study:

• To investigate the role of NMDARs in fear conditioning under different prediction error conditions.
• To challenge the established view on NMDAR necessity in fear memory acquisition.

Main Methods:

• Male rats received BLA infusions of the NMDAR antagonist D-AP5.
• Fear conditioning was assessed using Pavlovian paradigms with surprising or expected foot shocks.
• Electrophysiology was used to examine AMPA receptor function in BLA interneurons.

Main Results:

• NMDAR blockade in the BLA disrupted fear acquisition when the foot shock was surprising.
• Fear acquisition was spared when the foot shock was expected based on context and stimuli.
• Under expected shock conditions, fear acquisition relied on calcium-permeable AMPA receptors (CP-AMPA).

Conclusions:

• NMDAR activation is not universally required for fear conditioning.
• The involvement of NMDARs in fear conditioning is dependent on prediction errors related to aversive events.
• Fear conditioning to expected aversive events involves CP-AMPA receptors and occurs independently of NMDARs in the BLA.