Burst Dynamics Under Mixed Nmda and Ampa Drive in the Models of the Lamprey Spinal Cpg

Spinal CPG of lamprey is modeled using chains of nonlinear oscillators. Each oscillator represents a small neuron population capable of bursting under mixed NMDA and AMPA drive. Parameters of the oscillator are derived from detailed conductance-based neuron models. Analysis and simulations of dynamics of a single oscillator, a chain of excitatory oscillators and a chain of two pairs of excitatory and inhibitory oscillators in each segment are done. Roles of asymmetric couplings and additional rostral drive are studied. Conditions for generation of a traveling wave with one cycle per chain length in a realistic frequency range are specified. Results are verified in large-scale spinal cord simulations and correspond to available experimental data