Differential excitatory control of 2 parallel basket cell networks in amygdala microcircuits

2017. december 8.

The perisomatic region of neurons refers collectively to the membrane surface of the cell body or soma, proximal dendrites, and axon initial segment. This is a unique functional domain in which the activity of a neuron can be controlled in the most effective manner. In the cerebral cortex, the perisomatic region of excitatory principal cells is solely innervated by inhibitory interneurons, which can be divided into 3 functional groups: axo-axonic cells and 2 types of basket cells. The reason why 3 distinct types of inhibitory cells are specialized to control principal cell firing is still unknown. To reveal the possible differences in the role of the 3 interneuron types played in cortical operation, we have investigated the organizing principles of synaptic communication between principal cells and inhibitory cell types in the basal nucleus of the amygdala. In this cortical structure, known to be critical for affective behavior, we revealed that the 2 basket cell types avoid innervating each other but contact axo-axonic cells. Both basket cell types have a similar potency to control principal cell firing, but they receive excitatory input from principal cells with entirely distinct features. Our data suggest fundamentally different functions for the 2 parallel basket cell networks in amygdala operation.

Fig 1. Cholecystokinin-expressing basket cells (CCKBCs) and parvalbumin-containing basket cells (PVBCs) form 2 parallel inhibitory circuits, but both innervate axo-axonic cells (AACs)


Andrási T, Veres JM, Rovira-Esteban L, Kozma R, Vikór A, Gregori E, et al. (2017) Differential excitatory control of 2 parallel basket cell networks in amygdala microcircuits. PLoS Biol 15(5): e2001421. https://doi.org/10.1371/journal.pbio.2001421