FUNCTIONAL SYNERGISM BETWEEN PUTATIVE GAMMA-AMINOBUTYRATE-CONTAINING NEURONS AND PYRAMIDAL NEURONS IN PREFRONTAL CORTEX

The responses of putative gamma-aminobutyratergic interneurons (fast-s piking) and pyramidal (regular-spiking) cell pairs were compared in mo nkeys performing visual and memory-guided oculomotor tasks. Both fast- and regular-spiking neurons had similar receptive fields, indicating that gamma-aminobutyratergic interneurons carry a specific information al signal, as opposed to providing nonspecific modulation. However, th e responses of the pairs were inverted and the timing of excitatory an d inhibitory responses appeared to be phased, a property consistent wi th gamma-aminobutyrate-mediated shaping of receptive fields. These obs ervations (i) provide evidence that interneurons and pyramidal cells c an be differentiated in vivo and (ii) begin to elucidate the role of g amma-aminobutyratergic mechanisms in cognition.