Paul Tiesinga, Ph.D.

Dept. of Physics and Astronomy,
University of North Carolina

"The role of interneuron diversity in the cortical circuit for attention."

Receptive fields of neurons in cortical area V4 are large enough to fit multiple stimuli, making V4 the ideal place to study the effects of selective attention at the single neuron level. Experiments have revealed evidence for stimulus competition and have characterized the effect thereon of spatial and feature-based attention. We developed a biophysical model with spiking neurons and conductance-based synapses. In order to account for the comprehensive set of experimental results, it was necessary to include in the model two types of interneurons: feedforward interneurons (FFI) and top-down interneurons (TDI). We propose that the FFI correspond to fast-spiking, parvalbumin-positive basket cells and that the TDI correspond to cells with a double-bouquet morphology which are immunoreactive to calbindin or calretinin.

Taken together, the model results provide an experimentally testable hypothesis for the behavior of two interneuron types under attentional modulation.