Phase-locked responses to pure tones in guinea pig auditory cortex

Phase-locked responses to pure tones are a characteristic of most auditory cells at the level of the brain stem and allow sophisticated analyses based on coincidence detection. Phase-locking to tones has not previously been s hown at the level of the auditory cortex in single unit studies. We have no w identified phase-locked responses in 10% of low-frequency (< 1 kHz) units in the ventrorostral belt, a strip of cortex immediately ventral to the pr imary auditory area. All of these units showed phase-locking in their respo nse to binaural tone pips of 60-200 Hz and showed narrow band pass characte ristics within this range. NeuroReport 11:3989-3993 (C) 2000 Lippincott Wil liams & Wilkins.