Adaptive Responding to Stimulus-Outcome Associations Requires Noradrenergic Transmission in the Medial Prefrontal...

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Cognitive Neuroscience

Background:

• Organisms must constantly update their knowledge in dynamic environments.
• The prefrontal cortex regulates adaptive behavior, but specific subregion roles are unclear.
• Updating stimulus-outcome (S-O) associations is vital for adapting to changing environments.

Purpose of the Study:

• To investigate the roles of the medial prefrontal cortex (mPFC) and orbitofrontal cortex (OFC) in updating Pavlovian S-O associations.
• To examine the involvement of noradrenaline (NA) projections from the locus ceruleus (LC) to the mPFC and OFC in this process.

Main Methods:

• Chemogenetic inhibition of mPFC and OFC neurons in male rats during a contingency degradation task.
• Tracing NA projections from the LC to the mPFC and OFC using novel retrograde vectors.
• Chemogenetic inhibition of NA projections to the mPFC and OFC.

Main Results:

• Inhibition of mPFC, but not OFC, neurons impaired adaptive responding to contingency degradation.
• NA projections to both mPFC and OFC were observed, with similar input amounts.
• Inhibition of NA projections to the mPFC, but not OFC, impaired adaptive updating.

Conclusions:

• Findings demonstrate functional parcellation within the prefrontal cortex.
• mPFC, specifically its NA projections, plays a critical role in updating Pavlovian S-O associations.
• This highlights the importance of the mPFC-NA pathway for cognitive flexibility.