Vagus-nerve-stimulation-induced modulation of auditory thalamic and cortical activities

Vagus nerve stimulation (VNS) reduces intractable epileptic seizures. VNS is also likely to improve higher brain functions such as cognition and memory, although the mechanisms of action remain speculative. In this study, we examined the effects of VNS on auditory perception. Using a depth microelectrode array, we investigated neural activities in the auditory cortex and thalamus of anesthetized rats in terms of reproducibility and temporal resolution of sound evoked responses. Consequently, we found that, in the auditory cortex, VNS improved reproducibility of neural activities in response to characteristic-frequency tones and strengthened adaptation to repetitive clicks. On the other hand, in the thalamus, VNS had no significant effect on reproducibility and temporal resolution of sound evoked responses. Thus, VNS may affect auditory perception.