CELLULAR GENERATORS OF THE CORTICAL AUDITORY EVOKED-POTENTIAL INITIALCOMPONENT

Cellular generators of the initial cortical auditory evoked potential (AEP) component were determined by analyzing laminar profiles of click -evoked AEPs, current source density, and multiple unit activity (MUA) in primary auditory cortex of awake monkeys. The initial AEP componen t is a surface-negative wave, N8, that peaks at 8-9 msec and inverts i n polarity below lamina 4. N8 is generated by a lamina 4 current sink and a deeper current source. Simultaneous MUA is present from lower la mina 3 to the subjacent white matter. Findings indicate that thalamoco rtical afferents are a generator of N8 and support a role for lamina 4 stellate cells. Relationships to the human AEP are discussed.