Extracellular matrix dynamism during auditory perceptual learning

Perceptual learning (PL) refines sound discrimination or detection, facilitating linguistic skills and hearing prosthetic use, but typically requires extensive training. Understanding its neural mechanisms could accelerate skill acquisition. Cortical plasticity underlies PL, but its regulation is not fully understood. The extracellular matrix (ECM)—a molecular network surrounding neurons and glia—was once considered a static barrier to adult plasticity, but recent evidence suggests that it transiently degrades during training, enabling plasticity, and gradually reforms to stabilize changes over several days. To determine if PL engages similar dynamics, we trained gerbils on an auditory PL task and examined ECM expression in the auditory cortex. The ECM rapidly degraded and renormalized within 24 h of each training session. Strikingly, this remodeling cycle disappeared over successive days. Remodeling was absent in the somatosensory cortex, and in control animals presented with unpaired sounds and reinforcement cues. Enzymatic ECM ablation impaired PL without affecting associative learning, and post-training ablation appeared to destabilize the perceptual skill memory. Our results suggest that ECM remodeling facilitates PL by enabling and stabilizing cortical plasticity, and offer a new framework in which the experience-dependent decline in remodeling contributes to the long-term maintenance of perceptual skill memories.