Dynamic control of auditory activity during sleep: correlation between song response and EEG.

The song nucleus high vocal center (HVC) sends neural signals for song production and receives auditory input. By using electroencephalography (EEG) to objectively identify wake/sleep state, we show that HVC auditory responses change with physiological states. Comparison of EEG and HVC records revealed that HVC response to auditory stimuli is greatest during slow-wave sleep. During slow-wave sleep, HVC neurons responded preferentially to the bird's own song. Strikingly, both spontaneous and forced waking during sleep caused HVC auditory responses to cease within milliseconds of an EEG-measured state change. State-dependent phenomena in downstream nuclei, such as robustus archistriatalis, are likely to be derivatives of those in HVC.