Precise sound characteristics drive plasticity in the primary auditory cortex with VNS-sound pairing

IntroductionRepeatedly pairing a tone with vagus nerve stimulation (VNS) alters frequency tuning across the auditory pathway. Pairing VNS with speech sounds selectively enhances the primary auditory cortex response to the paired sounds. It is not yet known how altering the speech sounds paired with VNS alters responses. In this study, we test the hypothesis that the sounds that are presented and paired with VNS will influence the neural plasticity observed following VNS-sound pairing.MethodsTo explore the relationship between acoustic experience and neural plasticity, responses were recorded from primary auditory cortex (A1) after VNS was repeatedly paired with the speech sounds 'rad' and 'lad' or paired with only the speech sound 'rad' while 'lad' was an unpaired background sound.ResultsPairing both sounds with VNS increased the response strength and neural discriminability of the paired sounds in the primary auditory cortex. Surprisingly, pairing only 'rad' with VNS did not alter A1 responses.DiscussionThese results suggest that the specific acoustic contrasts associated with VNS can powerfully shape neural activity in the auditory pathway. Methods to promote plasticity in the central auditory system represent a new therapeutic avenue to treat auditory processing disorders. Understanding how different sound contrasts and neural activity patterns shape plasticity could have important clinical implications.

Automated summary

Pairing sound contrasts with VNS can significantly influence neural activity in the auditory pathway, leading to increased response strength and discriminability. However, pairing VNS with only one sound does not have the same effect on neural responses. Understanding the impact of different sound contrasts and neural activity patterns on plasticity could have important clinical implications for treating auditory processing disorders.