Central amygdala circuit dynamics underlying the benzodiazepine anxiolytic effect

Area of Science:

• Neuroscience
• Pharmacology
• Anxiety Disorders Research

Background:

• Benzodiazepines (BZDs) are widely used for anxiety but their precise neuronal mechanisms are unclear.
• Understanding the neural circuits involved in BZD action is critical for developing targeted anxiety treatments.

Purpose of the Study:

• To elucidate the neuronal circuit interactions underlying the anxiolytic effects of benzodiazepines.
• To identify specific brain regions and neuronal populations mediating diazepam's therapeutic action.

Main Methods:

• Combined connectome mapping with immediate early gene (IEG) activation to pinpoint drug targets.
• Utilized deep brain calcium imaging to observe brain-wide neuronal activity shifts.
• Employed chemogenetic silencing to determine the necessity and sufficiency of specific neuron types.

Main Results:

• Identified the central amygdala (CEA) as a key site for diazepam's (DZP) anxiolytic effects.
• Observed that DZP alters neuronal activity within CEA microcircuits.
• Demonstrated that PKCδ+/SST- neurons in the lateral CEA (CEAl) are essential for DZP's anxiolytic action.

Conclusions:

• Benzodiazepines may exert anxiolytic effects by inhibiting the transmission of aversive signals via the CEA.
• This action is partly mediated by interactions with CEAl SST+/PKCδ- neurons, reshaping intra-CEA circuits.
• The study provides a framework for identifying drug-target interactions and highlights the CEA's role in anxiety.