[NEST Users] Izhikevich Simulation

Dear Nest Users, Has anyone used any NEST Synapse Models to create Gamma Rhythms during a simulation with the NEST Izhikevich Neuron model? My simulation, which uses the Stdp-Synapse model (additive type) does not appear to be converging into gamma rhythms (w/bi-model wt distribution) using super-threshold poisson point process (ref: Polychronization Computation With Spikes (Izhikevich, 2006), - DOI: 10.1162/089976606775093882 <https://doi.org/10.1162/089976606775093882>) - - - - Thanks for any suggestions, Best Regards, --Allen