Parietal-Frontal Pathway Controls Relapse of Fear Memory in a Novel Context.

Area of Science:

• Neuroscience
• Behavioral Science

Background:

• Fear responses impact daily life and uncertainty processing.
• Relapse of extinguished fear in novel situations challenges exposure-based therapies.
• Mechanisms linking novel contexts to fear relapse are not well understood.

Purpose of the Study:

• Investigate the neural circuits and mechanisms underlying fear renewal in novel contexts.
• Identify the role of the posterior parietal cortex (PPC) and anterior cingulate cortex (ACC) in fear relapse.

Main Methods:

• Utilized a context-dependent fear renewal model.
• Employed optogenetics, histology, in vivo/ex vivo electrophysiology, and pharmacology.
• Examined functional circuits between the PPC and ACC.

Main Results:

• The PPC-to-ACC pathway was identified as critical for fear relapse in novel contexts.
• Observed increased activity in ACC neurons receiving PPC projections and enhanced synaptic activity in PPC-to-ACC neurons projecting to the basolateral amygdala.
• Parvalbumin-expressing interneurons were found to control context-dependent fear renewal, which was inhibited by fluoxetine.

Conclusions:

• The PPC-to-ACC pathway mediates the relapse of extinguished fear in novel environments.
• Findings provide significant insights into the neural mechanisms governing fear renewal.
• This pathway represents a potential target for interventions aimed at preventing fear relapse.