BLA (Basolateral amygdalar nucleus) synapses onto BLA glutamatergic principal neurons

In 7 biocytin-filled PV-expressing axo-axonic cells, axon terminals formed symmetrical synapses mainly on axon initial segments, not on somata or dendrites. Most sampled boutons (41 of 55) contacted axon segments 0.5 to 1 µm in diameter, and the most proximal axon was rarely targeted.

Made by an AI model reading the paper (claude-opus-5-5, extract@0.3.0); a second AI model (claude-opus-5-5) disagrees. “The subject is the whole BLA region, but the paper's presynaptic element is the PV-expressing axo-axonic cell population, not the nucleus.”