Cortical and Thalamic Interaction with Amygdala-to-Accumbens Synapses

Area of Science:

• Neuroscience
• Cellular and Molecular Neuroscience

Background:

• The nucleus accumbens shell (NAcSh) integrates glutamatergic inputs to modulate emotional and motivational behaviors.
• Understanding the interaction of these inputs is crucial for deciphering NAcSh function.

Purpose of the Study:

• To investigate the anatomical and physiological interactions between basolateral amygdala projections (BLAp), medial prefrontal cortex projections (mPFCp), and paraventricular nucleus of the thalamus projections (PVTp) to the NAcSh.
• To elucidate how these interactions contribute to information processing within the NAcSh.

Main Methods:

• Utilized dual-color SynaptoTag and backfilling spine imaging in mice to map synaptic contacts.
• Employed dual-rhodopsin optogenetics in brain slices to assess functional interactions.

Main Results:

• Identified that BLAp, mPFCp, and PVTp primarily target NAcSh medium spiny neuron dendrites.
• Observed heterosynaptic interactions and shared spine contacts between BLAp and mPFCp/PVTp.
• Demonstrated dendritic summation between BLAp and PVTp/mPFCp inputs.
• Found that BLAp activation enhanced PVTp transmission but not mPFCp transmission.

Conclusions:

• The basolateral amygdala projection interacts anatomically and functionally with medial prefrontal cortex and paraventricular nucleus of the thalamus projections in the nucleus accumbens shell.
• These interactions provide mechanisms for integrating information from different brain regions to shape behavioral output.