Intrinsic Circuits in the Lateral Central Amygdala.

Area of Science:

• Neuroscience
• Molecular and Cellular Neuroscience
• Systems Neuroscience

Background:

• The lateral central amygdala (CeL) is vital for fear learning and emotional processing.
• Understanding the local circuitry within the CeL is essential but remains incomplete.

Purpose of the Study:

• To characterize the intrinsic neuronal connections within the lateral central amygdala (CeL).
• To investigate the roles of specific neuronal populations (SOM+ and SOM-) in CeL circuitry.

Main Methods:

• Paired whole-cell patch-clamp recordings in wild-type and SOM-Cre mice.
• Immunohistochemistry for protein kinase Cδ (PKCδ).
• Optogenetic activation of somatostatin-expressing (SOM+) and non-somatostatin-expressing (SOM-) neurons.

Main Results:

• Approximately 29% of local CeL neurons form inhibitory connections, with single inputs capable of silencing postsynaptic neurons.
• The most prevalent local connections were between PKCδ(-) neurons and between SOM(+) neurons.
• Both SOM(+) and SOM(-) neurons innervate most CeL neurons, with stronger connections observed between like neuronal types.

Conclusions:

• The CeL exhibits a complex intrinsic inhibitory network.
• Specific neuronal populations, including SOM+ neurons, play significant roles in CeL circuit organization.
• These findings provide a foundation for future studies on CeL circuit function in behavior.