ErbB4 signaling in the prelimbic cortex regulates fear expression

Area of Science:

• Neuroscience
• Molecular Biology
• Psychiatry

Background:

• Abnormal fear processing is central to psychiatric disorders like PTSD.
• The medial prefrontal cortex (mPFC) plays a key role in fear expression.
• Molecular mechanisms of fear regulation in the mPFC are not fully understood.

Purpose of the Study:

• To investigate the role of Neuregulin-1 (NRG1)/ErbB4 signaling in the mPFC in modulating fear expression.
• To determine the specific brain regions and cell types involved in this pathway.

Main Methods:

• Utilized tone-cued fear conditioning paradigms in rodent models.
• Employed techniques such as NRG1 neutralization, ErbB4 inhibition/ablation, and genetic manipulation (PV-Cre;ErbB4-/- mice).
• Assessed fear conditioning behavior and gene expression changes in the mPFC.

Main Results:

• Tone-cued fear conditioning increased NRG1 expression in the mPFC.
• Inhibition or ablation of ErbB4 in the prelimbic (PL) cortex, but not infralimbic cortex, impaired fear conditioning.
• ErbB4 deletion in parvalbumin (PV) neurons specifically disrupted fear conditioning.
• Overexpression of ErbB4 in the PL cortex rescued fear conditioning deficits in relevant mouse models.

Conclusions:

• Identified a novel NRG1/ErbB4 signaling pathway in the PL cortex regulating fear expression.
• This pathway involves PV interneurons and is critical for fear conditioning.
• Findings offer insights into the pathophysiology of schizophrenia and potential therapeutic targets for PTSD.