Primary auditory cortex activity during early retrieval supports later extinction learning.

Emotional flexibility-the ability to update threat associations when contingencies change-is essential for adaptive behavior, yet the underlying cortical mechanisms remain unclear. Here, we used chemogenetic inhibition of primary auditory cortex (A1) principal neurons to test whether activity in this region during early or long-term fear memory retrieval is required for remote memory consolidation and/or subsequent extinction learning. We hypothesized that since extinction involves competition between threat and safety representations, weighting memory traces in the same cortical region could facilitate extinction acquisition. Male and female C57BL/6J mice underwent auditory fear conditioning with a white noise conditioned stimulus (CS) paired with a foot shock unconditioned stimulus (US). Mice received intraperitoneal injections of clozapine-N-oxide (CNO), the chemogenetic ligand, prior to early (day 1) or long-term (day 15) retrieval. All mice were also tested on day 30 to assess the effects of early or late inhibition on remote recall in the absence of CNO. Early or late inhibition did not produce memory impairments at any retrieval time point. However, early inhibition delayed extinction acquisition and impaired extinction memory. Conversely, long-term inhibition had no significant effect on subsequent extinction. In males, extinction memory deficits were associated with elevated freezing during remote retrieval, whereas females showed greater behavioral variability. These findings suggest that disrupting cortical activity during early retrieval impairs extinction learning, underscoring a key role for A1 in emotional flexibility. More broadly, they support the idea that cortical integration of threat and safety associations is essential for appropriately weighting emotional responses.