This 2-cell cortical circuit model consists of a negative feedback loop between a single compartment pyramidal cell and a single compartment interneuron. Ion concentrations in the extra- and intracellular spaces are included in the model. The model is used to test the contribution of cortical inhibitory interneurons to the initiation of cortical spreading depression, as characterized by spike block in the pyramidal cell. Results show that interneuronal inhibition provides a wider dynamic range to the circuit and generally improves stability against spike block. Despite these beneficial effects, strong interneuronal firing contributed to rapidly changing extracellular ion concentrations, which facilitated hyperexcitation and led to spike block first in the interneuron and then in the pyramidal cell. The model results demonstrate that while the role of interneurons in cortical microcircuits is complex, they are critical to the initiation of pyramidal cell spike block and CSD. See reference below for more details.
Region(s) or Organism(s): Neocortex
Model Concept(s): Spreading depression
Simulation Environment: FORTRAN