Barrel Cortex Microcircuit

Qian-Quan Sun PhD is a researcher at the The laboratory of Neural Development and Learning at University of Wyoming, Laramie. His research focuses on cortical microcircuits using anatomical and electrophysiological techniques. He enlisted me to develop a simulation of the Barrel cortex using traced cells obtained in his laboratory to test a hypothesis of synchronized firing of 'fast-spiking' (FS) cells due to gap junctions between them. The simulation consisted of two FS cells and two Spiny Stellate (SS) cells interconnected with AMPA, NMDA and GABAa synapses as well as gap junctions between the FS cells. Membrane biophysics was based on ( Fohlmeister JF, Coleman P.A. & Miller RF. Modeling the repetitive firing of retinal ganglion cells. Brain Res. 1990 Mar 5;510(2):343-5. ) with modifications in agreement with data reported by ( Beierlein M, Gibson JR, Connors BW Two dynamically distinct inhibitory networks in layer 4 of the neocortex. J Neurophysiol. 2003 Nov;90(5):2987-3000 ) Further fine-tuning of the model followed uEPSP and uIPSP data obtained in Dr. Sun's laboratory.

Panels from the simulation interface show (left) the cross-correlation function between
FS cells with gap junctions. On the right are tracings of two FS and two SS cells.