Prefrontal parvalbumin interneurons shape neuronal activity to drive fear expression

Area of Science:

• Neuroscience
• Behavioral Neuroscience
• Computational Neuroscience

Background:

• Neuronal synchrony is crucial for information processing and behavior.
• GABAergic interneurons regulate synchrony via oscillations.
• The dorsomedial prefrontal cortex (dmPFC) controls fear behavior via projections to the basolateral amygdala (BLA).

Purpose of the Study:

• Investigate the role of prefrontal circuits in the temporal control of fear behavior.
• Determine the causal relationship between prefrontal neuronal activity and fear expression.

Main Methods:

• Single-unit recordings in behaving mice.
• Optogenetic manipulations to control neuronal activity.
• Analysis of neuronal firing patterns and local theta oscillations.

Main Results:

• Phasic inhibition of prefrontal parvalbumin interneurons (PVINs) causally relates to fear expression.
• PVIN inhibition disinhibits projection neurons, synchronizing their firing.
• This synchronization is mediated by resetting local theta oscillations.

Conclusions:

• PVINs play a critical role in coordinating prefrontal neuronal activity for fear expression.
• Two mechanisms involving PVINs precisely control and enhance projection neuron activity.
• This provides insight into the neural circuitry underlying emotional behavior.