The aim of the work is to build a radiophysical generator of neuron-like activity with a frequency tunable in various ways, corresponding to modern ideas about the structure of the hippocampus and the generation of pathological epileptic rhythms in it. Methods. The elements of the generator are radio engineering implementations of the complete FitzHugh– Nagumo neuron and the electronic implementation of a chemical synapse in the form of a sigmoid function with a delayed argument. The simulation was carried out in the SPICE simulator. Results. Various ways of introducing delay into the coupling are considered: an ideal delay line, a phase filter with a rheostat, one tunable Bessel filter, and a sequence of non-tunable Bessel filters. For circuit implementation, the approach using a Bessel filter with a rheostat is recognized as optimal as a compromise between simplicity and minimization of signal distortion. The dependences of the oscillation frequency on the number of elements in the ring and the delay time are constructed. The bistability of generation regimes is studied for certain values of the parameters. The effect of inclusion of inhibitory elements (interneurons) in the circuit is considered. Conclusion. The constructed ring generator models the experimentally observed properties of the dynamics of epileptic discharge fundamental frequency in limbic epilepsy. It is able to reproduce the occurrence of oscillations as a result of external short-term driving, smooth and sharp frequency tuning, the coexistence of different modes with the same parameters.

We propose a method for reconstructing links in a chain of unidirectionally coupled systems by means of three tests for estimating direct and mediated coupling with the aid of Granger conditional...

While synchronization in the brain neural networks has been studied, the emergency of the main oscillation frequency and its evolution at different normal and pathological states remains poorly investigated. We propose a new concept of the formation of a main frequency in limbic epilepsy. The idea is that the main frequency is not a result of the activity of a single cell, but is formed due to collective dynamics in a ring of model neurons connected with delay. The individual cells are in an excitable mode providing no self-oscillations without coupling. We considered the ring of a different number of Hodgkin–Huxley neurons connected with synapses with time delay. We have shown that the proposed circuit can generate oscillatory activity with frequencies close to those experimentally observed. The frequency can be varied by changing the number of model neurons, time delay in synapses and coupling strength. The linear dependence of the oscillation period on both coupling delay and the number of neurons in the ring was hypothesized and checked by means of fitting the values obtained from the numerical experiments to the empirical formula for a constant value of coupling coefficient.