Axon initial segment dynamics during associative fear learning

The axon initial segment (AIS) is the site of action potential generation and exhibits structural and functional plasticity upon adaptation of neuronal excitability and disease. Performing in vivo longitudinal two-photon imaging of AIS in the medial prefrontal cortex of male mice, we reveal dynamic AIS remodeling during associative fear learning and extinction. These results demonstrate that AIS plasticity is not only crucial for homeostatic adaptation but also a hallmark of memory formation.