The mouse dorsal peduncular cortex encodes fear memory.

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Systems Neuroscience

Background:

• The medial prefrontal cortex (mPFC) regulates fear, with subregions like Cg1, PL, and IL involved in fear promotion and suppression.
• The dorsal peduncular (DP) cortex's role in fear and memory remains largely unexplored, despite its ventral mPFC location.
• Previous research suggests a complex, sometimes contradictory, role for ventral mPFC in fear regulation.

Approach:

• Utilized cFos immunohistochemistry, whole-cell electrophysiology, fiber photometry, and neural tagging to investigate DP cortex function.
• Examined DP neuron plasticity, cue-associated activity during learning and retrieval, and reactivation patterns.
• Employed optogenetics to manipulate fear learning-related DP neural ensembles and assess behavioral outputs (freezing).

Key Points:

• DP neurons demonstrate learning-related plasticity and acquire cue-associated activity.
• Activated DP neurons during learning are preferentially reactivated during fear memory retrieval.
• Optogenetic activation of DP ensembles promotes freezing, while silencing suppresses it.

Conclusions:

• The DP cortex unexpectedly functions in cued fear memory encoding, not fear extinction.
• DP neurons play a critical role in promoting fear responses.
• Findings reveal novel organizational principles within the mPFC's dorsoventral axis regarding fear processing.